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ILLINOIS BIOLOGICAL 
 MONOGRAPHS 
 
 PUBLISHED QUARTERLY 
 
 UNDER THE AUSPICES OF THE GRADUATE SCHOOL 
 
 BY THE UNIVERSITY OF ILLINOIS 
 
 VOLUME X 
 
 Urbana, Illinois 
 1926 
 
Editorial Committee 
 
 Stephen Alfred Forbes William Trelease 
 
 Henry Baldwin Ward 
 
5 7 . -b 
 XLL 
 
 vJOco 2 
 
 TABLE OF CONTENTS 
 VOLUME X 
 
 NUMBERS PAGES 
 
 1. Studies on the Avian Species of the Cestode Family Hymenolepididae. 
 
 By R. L. Mayhew. With 9 plates and 2 text figures 1-120 
 
 2. Some North American Fish Trematodes. By H. W. Manter. With 6 
 
 plates, 2 charts, and 1 text figure 127-264 
 
 3. Comparative Studies on Furcocercous Cercariae. By H. M. Miller, Jr. 
 
 With 8 plates and 2 text figures .'.... 265-370 
 
 4. A Comparison of the Animal Communities of Coniferous and Deciduous 
 
 Forests. By I. H. Blake. With 16 plates and 25 tables 371-520 
 
 
Digitized by the Internet Archive 
 
 in 2011 with funding from 
 
 University of Illinois Urbana-Champaign 
 
 http://www.archive.org/details/studiesonaviansp10mayh 
 
ILLINOIS BIOLOGICAL 
 MONOGRAPHS 
 
 Vol. X January, 1925 No. 1 
 
 Editorial Committee 
 
 Stephen Alfred Forbes William Trelease 
 
 Henry Baldwin Ward 
 
 Published under the 
 
 Auspices of the Graduate School by 
 
 tee University of Illinois 
 
Copyright, 1925. by the University of Illinois 
 Distributed. December 2o, 1925 
 
STUDIES ON THE AVIAN SPECIES OF THE 
 CESTODE FAMILY HYMENOLEPIDIDAE 
 
 WITH 9 PLATES AND 2 TEXTFIGURES 
 
 BY 
 
 ROY LEWIS MAYHEW 
 
 Contributions from the 
 
 Zoological Laboratory of the University of Illinois 
 
 under the direction of Henry B. Ward 
 
 No. 260 
 
THESIS 
 
 SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE 
 
 DEGREE OF DOCTOR OF PHILOSOPHY IN ZOOLOGY IN THE GRADUATE 
 
 SCHOOL OF THE UNIVERSITY OF ILLINOIS 
 
 1924 
 
TABLE OF CONTENTS 
 
 Page 
 
 Introduction ' 
 
 Methods of Technique ° 
 
 Historical Account of the Family Hymenolepididae 9 
 
 Historical Account of the Genera 
 
 Genus Oligorchis Fuhrmann 1906 12 
 
 Genus Hymenolepis Weinland 1858 12 
 
 Characters Previously Used to Divide the Genus 16 
 
 Genus Diorchis Clerc 1903 21 
 
 Genus Haploparaxis Clerc 1903 21 
 
 Proposed Revision of the Genus Hymenolepis 23 
 
 Phylogeny of Species in the Genus Hymenolepis 29 
 
 Key to Subfamilies and Genera of Family Hymenolepididae 32 
 
 Family Hymenolepididae (Ariola) 1899 
 Subfamily Oligorchinae 
 
 Genus Oligorchis Fuhrmann 1906 33 
 
 Oligorchis strangulatus Fuhrmann 1906 H 
 
 Oligorchis delachauxi Fuhrmann 1909 34 
 
 Oligorchis yorkei (Kotlan) 1923 34 
 
 Oligorchis longivaginosus N. Sp 34 
 
 Doubtful Species 
 
 Oligorchis paucitesticulatus Fuhrmann 1913 37 
 
 Subfamily Hymenolepididae (Perrier) 1897. Ransom 1909 (Emended) 
 
 Genus Hymenolepis Weinland 1858 38 
 
 Description of New Species 
 
 Hymenolepis lobulata N. Sp 43 
 
 Hymenolepis cuneata N. Sp 45 
 
 Hymenolepis sacciperium N. Sp 48 
 
 Genus Weinlandia Nov. Gen - 52 
 
 List of the Species of Weinlandia 52 
 
 Description of New Species 
 
 Weinlandia lateralis N. Sp 56 
 
 Weinlandia cyrtoides N. Sp 59 
 
 Weinlandia corvi N. Sp 62 
 
 Weinlandia macrostrobilodes N. Sp 65 
 
 Weinlandia introversa N. Sp 67 
 
 Weinlandia microcirrosa N. Sp 70 
 
 Weinlandia planestici N. Sp 73 
 
 Genus wardium Nov. Gen 76 
 
 Wardium caprimulgorum (Fuhrmann) 1906 76 
 
 Wardium capillaroides (Fuhrmann) 1906 76 
 
 Wardium ambiguum (Clerc) 1906 77 
 
 Wardium variabile N. Sp 77 
 
 Wardium f ryei N. Sp 80 
 
 Genus Echinorhynchotaenia Fuhrmann 1909 84 
 
 Echinorhyncotaenia tritesticulata Fuhrmann 1909 84 
 
 Echinorhyncotaenia nana Maplestone and Southwell 1922 84 
 
 Genus Hymenofimbria Skrjabin 1914 85 
 
 Hymenofimbria merganseri Skrjabin 1914 85 
 
 Genus Fimbriaria Froelich 1802 85 
 
 Fimbriaria fasciolaris (Pallas) 1781 86 
 
 Fimbriaria intermedia Fuhrmann 1914 86 
 
 Subfamily Diorchinae 
 
 Genus Diorchis Clerc 1903 87 
 
 Diorchis acuminata (Clerc) 1902 87 
 
Diorchis americana Ransom 1900 88 
 
 Diorchis flavescens (Krefft) 1871 88 
 
 Diorchis infiata (Rudolphi) 1809 89 
 
 Diorchis parviceps (von Linstow) 1872 89 
 
 Diorchis excentricus N. Sp 90 
 
 Subfamily Haploparaxinae 
 
 Genus Haploparaxis Clerc 1903 92 
 
 List of Species 92 
 
 Species Inquirendae 93 
 
 Summary 95 
 
 New Genera Described in This Paper 96 
 
 New Species Described in This Paper 96 
 
 Bibliography 97 
 
 Explanation of Plates ' 104 
 
 Index 123 
 
7] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 7 
 
 INTRODUCTION 
 
 The internal parasites of American birds are little understood, and it 
 was with the idea of finding out something about the species of cestodes 
 and extent of the infections that the investigations herein reported were 
 undertaken. A considerable quantity of material was obtained from the 
 collection of Professor H. B. Ward, who very kindly allowed me to use it. 
 In order to augment this and to secure fresh material, the examination 
 of as large a number of additional hosts as possible was undertaken. While 
 attending the session of the University of Washington Biological Station 
 in the summer of 1923, 45 birds obtained in the region of Friday Harbor, 
 Washington, were examined. A total of 537 hosts has been examined. 
 There were 60 different species among these, and of this number 40 were 
 found to be infected with cestodes. More than half of the specimens of 31 of 
 the species were found to be infected. Since a comparatively small number 
 of some of the host species was obtained, a further analysis of the records 
 would be of little value at present. 
 
 As mounts were prepared for a preliminary determination, it was ob- 
 served that a considerable number of species belonging to the genus 
 Hymenolepis Weinland 1858 had been obtained, and they were accordingly 
 brought together for further study. That a comparative study of the family 
 Hymenolepididae, and especially of the genus Hymenolepis would be an 
 important contribution to the existing knowledge of this group, was 
 evidenced by an examination of the literature. The numerous papers 
 examined disclosed descriptions of about 160 species which had been 
 assigned to the genus Hymenolepis, and that, beyond the comparisons 
 made by Fuhrmann, Cohn, Clerc, and Wolffhugel, no extensive com- 
 parative study of the genus had been undertaken. The conclusions herein 
 set forth are the result of a detailed study largely from the literature of 
 each of the species assigned to the genus Hymenolepis, and of the twelve 
 new species of which material has been obtained. But five North American 
 species have been reported exclusive of those imperfectly described by 
 Leidy (1887). 
 
 I wish to express my appreciation for the very helpful suggestions which 
 Professor Ward has given during the progress of the work, for the use of 
 his extensive library, and for the loan of specimens from his collection. 
 Thanks are due to Professor Frank Smith for the identification of a number 
 of the hosts, and to Professor T. C. Frye, Director of the University of 
 Washington Marine Station, for his interest and assistance in securing the 
 hosts for examination at Friday Harbor, Washington. 
 
8 ILLINOIS BIOLOGICAL MONOGRAPHS [8 
 
 METHODS OP TECHNIQUE 
 
 At the beginning a number of killing fluids were tried, with the uniform 
 result that acid fluids, such as Gilson's and Petrunkevitsch, react with the 
 calcareous bodies with such violence that large cavities resulted in the 
 preserved worm or the proglottids are puffed out balloon-like by the gas 
 formed within. The most satisfactory killing fluid was found to be a 
 saturated solution of corrosive sublimate in distilled water. This is allowed 
 to act from one to two hours, and replaced by 50 per cent alcohol for one 
 hour, then 70 and 85 per cent alcohol. Great care must be exercised to 
 extract all the corrosive sublimate before staining and mounting, as it 
 interferes with clearing. An effort should be made to secure the worms 
 as fully extended as possible, which may be done by gently pulling them 
 with the fingers protected by rubber gloves or by Looss' (1901) shaking 
 method. 
 
 The stain used for toto mounts and sections was in most cases Ehrlich's 
 acid hematoxylin, although Delafield's and Conklin's modified hematoxylin 
 were also about equally satisfactory. The procedure followed was to use 
 Ehrlich's acid hematoxylin full strength, staining in toto for two to four 
 days depending on the size of the worms, rinse off the stain with 50 per cent 
 alcohol, and destain in 10 per cent HC1. The length of time to be allowed 
 for destaining varies with the size of the specimen and can only be deter- 
 mined by practice, but usually only a few seconds or one minute is neces- 
 sary. The acid is neutralized by a saturated solution of Na2CO"3 in 70 per 
 cent alcohol. The stain is improved by allowing the stock solution to 
 concentrate through evaporation down to a very dark color and this may 
 be used over and over by first filtering to insure the removal of any sedi- 
 ment. The object of the process was to get the largest amount of stain 
 possible into the internal organs, and then to remove as much as possible 
 from the overlying tissues which retain it less strongly than do the repro- 
 ductive organs. Specimens stained and prepared in this manner were 
 cleared, the desired number of proglottids removed from the selected 
 regions for sectioning and the remainder mounted as totos. Specimens to 
 be sectioned should not have quite as much stain removed as those for 
 toto mounts, but the remaining pieces may be further destained for mount- 
 ing as totos if found to contain too much. Sections thus stained and 
 sectioned may be counterstained with eosin. The counterstain gives the 
 most satisfactory results if rather heavy since the ducts, as vasa deferentia, 
 take it up readily, and, unless too heavy, it does not obscure the other 
 structures. A small outline of the pieces of the cestodes from which pro- 
 glottids had been removed for sectioning was found very useful. These 
 are conveniently made on small cards the size of the slides, and may be 
 placed behind the slides in the boxes. They are useful also for recording 
 data as to length, width, etc., as well as to show readily the position of the 
 portions sectioned. 
 
9] STUDIES ON AVIAN SPECIES OF HVMENOLEPIDIDAE—MAYHEW 
 
 HISTORICAL ACCOUNT OF THE FAMILY HYMENOLEPIDIDAE 
 
 The name Hymenolepidae was first used by Ariola (1899), and he 
 defines the genus as follows: "con corpo di media o minima grandezza, 
 e scolice armato di una o piu corone di piccoli uncini." There is no list of 
 genera or discussion of its limits. The name Hymenolepididae was used 
 by Railliet and Henry (1909) and is synonymous with Hymenolepidae, 
 Echinocotylidae, and Dilepinidae, according to Ransom (1909) who gives 
 the following diagnosis: 
 
 "Taenioidea: Scolex with an armed rostellum, or without rostellum. 
 Hooks on the rostellum not hammer-shaped. Suckers usually unarmed. 
 A single, or rarely, a double, set of reproductive organs in each segment. 
 Genital pores marginal and bilateral, unilateral, or regularly or irregularly 
 alternate. Eggs with thin transparent shells. Adults in mammals, birds, 
 reptiles, and Amphibia." 
 
 Under this family he includes the following subfamilies and genera: 
 
 Dipylidiinae Stiles 1896 
 
 Dilepis Weinland 1858 Cyclustera Fuhrmann 1901 
 
 Trichocephaloides Sinitsin 1896 Laterotaenia Fuhrmann 1906 
 
 Lateriporus Fuhrmann 1907 Proorchida Fuhrmann 1907 
 
 Choanotaenia Railliet 1896 Cyclorchida Fuhrmann 1907 
 
 Monopylidium Fuhrmann 1899 Gryporhynchus Nordmann 1832 
 
 Anomotaenia Cohn 1900 Angularia Clerc 1906 
 
 Amoebotaenia Cohn 1899 Catenotaenia Janicki 1904 
 
 Liga Weinland 1857 Dipylidium Leuckart 1863 
 
 Leptotaenia Cohn 1901 Oochoristica Liihe 1898 
 
 Parvirostrum Fuhrmann 1907 Pancerina Fuhrmann 1899 
 
 Paruterininae 
 
 Paruterina Fuhrmann 1906 Metroliasthes Ransom 1900 
 
 Culcitella Fuhrmann 1906 Biuterina Fuhrmann 1902 
 
 Rhabdometra Kholodkovski 1906 Nematotaenia Liihe 1899 
 
 Anonchotaenia Cohn 1900 Stilesia Railliet 1893 
 
 Hymenolepidinae 
 Oligorchis Fuhrmann 1906 Diorchis Clerc 1903 
 
 Hymenolepis Weinland 1858 Haploparaxis Clerc 1903 
 
 Subgenus Hymenolepis Weinland 1858 
 
 Subgenus Echinocotyle Blanchard 1891 
 
10 ILLINOIS BIOLOGICAL MONOGRAPHS [10 
 
 The above list gives some idea of the size of the group. That it is a 
 poorly defined group is indicated by the lack of any statement of well 
 marked characters in the family diagnosis. It is best to consider briefly the 
 scolex and its hooks in a few genera in order to see the great variety of 
 types that are to be found. Dilepis has a double crown of hooks as do 
 Monopylidium, Anomotaenia, Liga, Parvirostrum, and five other genera. 
 Nine genera are defined as having a single crown of hooks and seven are 
 unarmed, while Angularia is stated to have "a zigzag crown of numerous 
 hooks (about 50)" and Dipylidium several rings of rose thorn hooks. Almost 
 every possible combination of pore arrangement with reference to the 
 margin and of the genital ducts to the excretory ducts is found. In Dilepis 
 the pores are unilateral and the ducts pass dorsal to the excretory vessels 
 and nerve, in Choanotaenia the pores are irregularly alternate and the 
 ducts pass between the excretory vessels and dorsal to the nerve, in Liga 
 the pores are regularly alternate and the ducts pass dorsal to the excretory 
 vessels and nerve, in Cyclorchida the pores are unilateral and the ducts 
 pass between the excretory vessels, Diplidium has a pore on each side 
 and a double set of reproductive organs, and in Anonchotaenia the pores 
 are irregularly or regularly alternate and the ducts pass ventral to the 
 excretory vessels and nerve. The number of testes varies from one to 50 
 in the different genera. The shape of the hooks differentiates the family 
 from the Davaineidae as defined by Ransom, but on the other hand some 
 species of Hymenolepis have hooks much like those of the Taeniidae, and 
 moreover, according to Ransom's statement, they may be anything but 
 hammer-shaped. The character of the uterus is not diagnostic since the 
 genus Catenotaenia is described as having a uterus consisting of a median 
 stern and lateral branches which is like that in Taeniidae. 
 
 Fuhrmann (1907) gives a classification from which two or three quo- 
 tations are now made: 
 
 "IV Familie Davaineidae 
 
 "Scolex mit einfach gebautem Rostellum, das mit einem doppelten 
 Kranz sehr zahlreicher, meist sehr kleiner hammerformiger Haken bewaff- 
 net ist. Genitalorgane einfach oder doppelt, Genitalpori beiderseitig, 
 einseitig oder unregelmassig abswechselnd. 
 
 "V Dilepinidae 
 
 "Scolex mit oder selten ohne bewaffnetes Rostellum, Saugnapfe 
 unbewaffnet. Genitalpori beiderseitig, einseitig, regelmassig abwechselnd. 
 Genitalorgane selten verdoppelt, meist einfach. 
 
 "VI Hymenolepinidae 
 
 "Scolex meist bewaffnet mit einem einfachen Kranz von Haken, selten 
 ohne oder mit nur rudimentarem Rostellum. Gleider immer breiter als 
 lang, Genitalporen miinden einseitig; die Geschlechtsgange gehen liber 
 die bieden Langsstamme des Wasserfasssystem und den Langsnerven 
 
11] STUDIES ON AVIAN SPECIES OF EYMEN0LEPID1DAE—MAYBEW 11 
 
 durch. Die Hoden in der Zahl von 1-4. Vas deferens immer kurz, mit 
 Samenblase, Uterus sackformig, Eier mit drei Hiillen. In Saugetieren und 
 Vogeln. 
 
 Fuhrmann (1908) places in the family Hymenolepididae the genera 
 Oligorchis, Hymenolepis (recognizing the subgenus Echinocotyle), Diorchis 
 and Aploparaksis. It is to be noted that the family Hymenolepididae is the 
 most sharply defined of the three referred to above which include those 
 genera which have been grouped more or less together by Ransom and by 
 Braun (1894-1900). The family Davaineidae is fairly well defined by the 
 character of the hooks and their arrangement, while the family Dilepinidae 
 contains a large group of genera differing rather widely in some respects, 
 the most outstanding difference being in the character of the reproductive 
 organs which may be either double or single in a prolgottid. Braun (1894- 
 1900) gives a classification which is upon less natural lines as is evidenced 
 when the following points are mentioned: Hymenolepis, (recognizing the 
 subgenus Drepanido taenia) Choanotaenia, and Dipylidium are placed in 
 the subfamily Dipylidiinae with a number of others, and Davainea, 
 Echinocotyle and Fimbriaria in the subfamily Davainiinae. 
 
 The genera which were placed in the family Hymenolepididae by Fuhr- 
 mann (1907) are Oligorchis Fuhrmann (1906a) Hymenolepis Weinland 
 1858, Diorchis Clerc 1903, and Aploparaksis Clerc 1803. A discussion of 
 the historical data relating to these genera is given in the following pages. 
 
12 ILLINOIS BIOLOGICAL MONOGRAPHS [12 
 
 HISTORICAL ACCOUNT OF THE GENERA 
 
 GENUS OLIGORCHIS FUHEMANN 1906 
 
 Fuhrmann (1906a: 217) describes the type species of this genus under 
 the name of 0. strangulatus. The material was taken from Elanoides 
 purcatits (L.) and was collected in Brazil. It is well described, and, since 
 a discussion of its structure and a diagnosis of the genus is given in the 
 systematic portion of this report, any further details seem unnecessary 
 at this point. 
 
 GENUS HYMENOLEPIS WEINLAND 1858 
 
 This is the oldest genus belonging to the family and has had about 
 fifteen times as many species assigned to it as to Haploparaksis Clerc 1903, 
 which is the next largest in size. Since an extended study of the species 
 assigned to it has been made, it is proper to trace rather fully its history, 
 especially the points which are concerned in the present study. 
 
 The genus was first described by Weinland in 1858 as a result of his 
 study of a number of pieces of a small tapeworm received from the collec- 
 tion of the Medical Improvement Society of Boston. The specimens were 
 from an infant 19 months old, and had been obtained in 1842. Since the 
 publication is rather inaccessible and since some very important character- 
 istics are pointed out, it seems advisable to refer to the details which 
 Weinland mentions at some length at this point. It was preserved in the 
 collection of the society under the name of "Bothriocephalus latits," 
 probably owing to the regularity and shortness of the joints. "Moreover, 
 there is a yellowish spot, clearly visible to the naked eye, situated about 
 the middle of each joint, which reminds us very much of the color and 
 situation of the genital organs as known in Bothriocephalus," according 
 to the account of Weinland. 
 
 "A careful examination, however, has taught us that there were in that 
 phial parts of at least six different specimens of a very characteristic 
 tapeworm, belonging neither to the genus Bothriocephalus nor to the 
 genuine Taeniae, — which latter, when limited in our sense, comprehend, 
 besides Taenia solium, only tapeworms of carnivorous mammals, — but to 
 a group of Taenoids, whose members thus far had only been found in small 
 omnivorous or insectivorous Mammalia (mice, shrew-mice, etc.) and birds. 
 It is widely different from Taenia solium, and its true congeners, in the 
 structure of its eggs, the situation of its genital openings, etc." 
 
 After a somewhat extended description of the external characters such 
 as measurements, shape of proglottids, Weinland discusses the reproductive 
 
13] STUDIES ON AVIAN SPECIES OF HYMEKOLEPIDIDAE—MAYHEW 13 
 
 organs as follows: "In relation to the genital organs, we have mentioned 
 above the yellowish spots lying near the middle line in the anterior part 
 of each joint, and it is for this that we have called the species Jlavopunctata. 
 These spots are the testicles, appearing under the microscope as a globular 
 gland, with another small one attached to it; this latter one runs out, 
 toward the side of the joint into a long slender canal, in which lies the 
 penis. The genital openings are situated all on one and the same side of 
 the worm, while in all true taenias known thus far, they are found irregu- 
 larly, now on one, now on the other side. The configuration of the uterus, 
 also, differs greatly from that in the genuine Taenias. There is no main- 
 stem in the midst with lateral branches, as in the latter; but, on the con- 
 trary, the eggs are crowded over the whole joint. It sometimes appears 
 as if they were arranged in straight lines along the joint; but this is cer- 
 tainly owing only to the regular lines of muscular contractions. Only fresh 
 specimens can decide ultimately the structure of the uterus. From a 
 careful dissection of the younger joints, we should judge that it consists 
 of globular blind sacs, located here and there in the joint, and connected 
 by fine tubes terminating finally in the vagina. The most characteristic 
 feature of this worm is its eggs, the number of which may be counted by 
 thousands in each ripe joint. They are very large, measuring .054 millim. 
 in diameter, and under a low power of the microscope appear as transparent 
 balls with a yellow dot in them. With a higher power, we easily distinguish 
 three distinct eggshells (Fig. 9, 1, a, b, c). The outside shell is translucent, 
 elastic, cracking in sharp angles under pressure and only .0007 millim. 
 thick; this shell is folded by application of glycerine. The second shell is 
 membranaceous and irregularly wrinkled, thinner than the first, and 
 
 immediately attached to it The large cavity which is formed by these 
 
 two outside shells contains a fluid, in which swims the small globular embryo 
 (measuring only 0.024 millim.), enclosed in a third shell, closely attached 
 to it, but of considerable thickness (0.001 millim.). We cannot state with 
 certainty that there are three pairs of spines to this embryo; if there are 
 any, they must be very small." 
 
 It is interesting to note that Weinland points out as characteristics 
 of the genus some which seem to be of almost universal occurrence in the 
 species assigned to it at the present time, namely, three egg shells, unilateral 
 genital pores, and a transverse sacular uterus. In all the descriptions of 
 the species the only suggestion that there are but two shells is by Ransom 
 (1909), in his account of H. cantaniana which reads as follows: "When 
 they first enter the uterus, the eggs have but a single thin membrane and 
 measure but 20/x in diameter. Later other membranes are developed, and 
 the egg (Fig. 29) in the final stage of development possesses two well- 
 defined shells, an inner one 27 to 35/* in diameter and an outer one 45 to 
 60/^ in diameter. Between the outer and inner shell is an intermediate 
 
14 ILLINOIS BIOLOGICAL MONOGRAPHS [14 
 
 finely granular layer limited by a very thin membrane internally and 
 externally." That this "very thin membrane" is the third shell or the rudi- 
 ment of it seems not at all improbable. 
 
 Concerning unilateral genital pores, the following species may be 
 referred to. Weinlandia asymetrica Fuhrmann 1918 is described as follows: 
 "nous avons observe que les pores sexuels qui sont unilateraux peuvent se 
 trouver, de temps en temps, mais tres rarement, sur le cote oppose." 
 Another observation is noted in Weinlandia lateralis in this report. Such 
 irregularities may be referred back to the ancestral condition of this very 
 large group of cestodes in which the position of the pores was probably irreg- 
 ularly alternate. Concerning the structure of the uterus, the only exception 
 to the transverse sacular type that has been found is that of H. pauciovata 
 Fuhrmann 1906, in which it is spherical in shape and centrally located in 
 the proglottid. 
 
 Weinland gives a proposed revision of the taenoid cestodes in a footnote 
 beginning on page 50, which is based primarily on the eggshell. It is briefly 
 outlined as follows: 
 
 Family Taenioidea; 4 suckers on the head and with marginal genital 
 openings. 
 
 Subfamily Sclerolepidota "with a hard, brittle, rather thick, and dark 
 colored eggshell." 
 
 Genus 1. Taenia, uterus with median stem with lateral branches, 
 
 head with two rows of hooks of the type of T. solium. 
 Genus 2. Acanthotrias Weinl. 1858 with three rows of hooks, type 
 Cysticercus acanthotrias which Weinland described on page 64 of 
 the same paper. 
 Genus. 3. Taeniarhynchus, Weinl. type T. mediocanellata, without 
 
 rostellum. 
 Genus 4. Echinococcifer Weinl. here belongs, T. echinococcus. 
 Genus 5. Diplocanthus Weinl. with a crown of bifid hooklets. 
 Subfamily Malacolepidota (Soft shelled tapeworms, shell thin and 
 transparent). 
 
 Genus 1. Hymenolepis Weinl. The name is derived from the Greek 
 words meaning membrane and shell. "Rarely 2 rows of hooklets 
 on the proboscis." Uterus consisting of ball-like blind sacs. 
 
 Subgenus Lepidotrias Weinl. with three eggshells, type T. 
 murina Dujardin. 
 
 Subgenus Dilepis Weinl. with two eggshells. Type T. angulata. 
 
 Genus 2. Proteocephalus Weinl. No proboscis nor hooklets, eggs 
 
 with 2 shells, head very changeable in shape. Type T. ambigua 
 
 Dujardin. 
 
 Genus 3. Alyselminthus Zeder, containing only T. cucumerina of 
 
 the dog, small spines arranged in a series of rows. 
 
15] STUDIES ON AVIAN SPECIES OF BYMENOLEPIDIDAE—MAYHEW 15 
 
 Since a discussion of the synonomy of most of the above divisions is 
 given by Stiles (1903), it does not seem advisable to go into the details 
 here, but since this study is especially concerned with the genus Hymen- 
 olepis, and its particular type of structure in order to determine which of 
 the proposed new genera shall retain this name, I must now go into this 
 somewhat in detail. 
 
 Grassi (1888) points out the synonomy of Taenia diminuta Rudolphi 
 1819, T. leptocephala 1825, and H. flavo punctata Weinland 1858. R. Blan- 
 chard (1891) gives a description of the anatomy of H. diminuta based on 
 the work of Grassi (1888)Zschokke (1885-88) and recognizes the genus 
 Hymenolepis Weinland. The important characters which distinguish it 
 are stated as follows: 
 
 "Corps petit, filiforme. Tete petite, pourvue d'un rostre rectractile, 
 bien developpe et arme d'une simple couronne de 24 a, 30 petits crochets, 
 ou rudimentaire et inerme. Cou long. Anneaux en dents de scie, beaucoup 
 plus larges que longs, en nombre rarement inferieur a 150. Pores sexuels 
 marginaux, perces sur le bord gauche des anneaux, la face ventrale de 
 ceux-ci etant celle qu'occupe l'appareil genital femalle. Appareil male 
 forme d'un tres petit nombre de testicules, le plus souvent de trois, dont 
 deux dans la moitie droite et un dans la moitie gauche de l'anneau. Anneau 
 mur transforme en un sac plein d'oeufs clairs, arrondis ou oblongs, et 
 entoures de trois coques tres ecartees les unes des autres. La coque interne 
 enserre l'oncosphere et n'a pas d'appareil pyriforme; elle presente parfois 
 un mamelon a. chaque pole. La larve est un Cryptocystis ou un Staphylocystis. 
 La migration s'accomplit soit entre deux organes d'un hote unique, soit, le 
 plus souvent, entre deux hotes differents, l'hote intermediate etant un 
 Insects ou un Myriapode." 
 
 Blanchard placed in this genus 14 species giving a short diagnosis of 
 each. These species are the following: 
 
 First Group — Armed Hymenolepis 
 H. murina Dujardin 1845 H. pistillum Dujardin 1845 
 
 H. nana von Siebold 1853 H. tiara Dujardin 1845 
 
 H. microstoma Dujardin 1845 H. erinacei Gmelin 1845 
 
 H. furcata Stieda 1862 H. bacillaris Goeze 1782 
 
 H. uncinata Stieda 1862 H. acuta Rudolphi 1819 
 
 H. scalaris Dujardin 1845 H. dccipiens Diesing 1850 
 
 Second Group — Unarmed Hymenolepis 
 H. relicta Zschokke 1888 H. diminuta Rudolphi 1819 
 
 Thus the genus Hymenolepis was established. The genus grew by 
 investigators referring previously described species to it, or by placing 
 new ones in it until it has reached the present great size of about 200 species. 
 The species found in birds have been brought together by the following 
 investigators. Fuhrmann (1908) has the most extensive list thus far 
 
16 ILLINOIS BIOLOGICAL MONOGRAPHS [16 
 
 published. It contains about 125 species listed under the host orders and 
 again by hosts. Ransom (1909) catalogues the names of about 70 species 
 with their hosts and references to the most satisfactory descriptions. 
 
 The literature dealing with this large collection of species is indeed any- 
 thing but satisfactory since no extensive attempt has been made to assemble 
 the important characters of the various groups of species and to determine 
 what are the relative value of these characters. One may identify a cestode 
 belonging to this genus only in one of the following ways. He may look 
 up the descriptions of as many species as are available, compare the size, 
 number and shape of hooks, arrangement of the testes, and other internal 
 organs with those structures on his specimens or he may take one of the 
 host lists, and look up the species described from the host from which his 
 specimens were obtained. The process by either method is time-consuming 
 and the result likely to be unsatisfactory because of the lack of sufficient 
 details in many of the descriptions. The proposed grouping of the species 
 incorporated in this report is a result of a comparative study of the descrip- 
 tions of all the species and of the new species herein described from North 
 American birds. 
 
 CHARACTERS PREVIOUSLY USED TO DIVIDE THE GENUS 
 
 The divisions of the genus Hymenolepis which have not yet been 
 discussed have been made upon the character of the hooks. The division 
 based upon the characters of the egg which was advocated by Weinland 
 (1858) has been discussed above. Railliet (1892) proposed a grouping of 
 the numerous species of cestodes of birds in particular into the two genera 
 of Drepanidotaenia and Dicranotaenia. At the end of a note in this paper, 
 which deals with some specimens of Taenia tenuirostris Rud., he defines 
 these proposed new genera and remarks as follows: 
 
 "Puisque l'occasion se presente de parler des Tenias des Oiseaux, je 
 tiens a signaler en passant la necessite de poursuivre la division de ce groupe, 
 entreprise deja par R. Blanchard. II est impossible, en effet, de laisser parmi 
 les Taenia s. str., c'est-a-dire a cote des grands Tenias de l'Homme et des 
 Mammiferes, l'ensemble des Teniades qui vivent dans l'intestin des 
 Oiseaux. 
 
 "Aussi proposerai-je d'etablir pour ceux-ci deux nouveaux genres, 
 bases principalement sur la forme des crochets: 
 
 1. Drepanidotaenia, pour les Teniades du type Taenia lanccolata 
 Bloch, dont le rostre est arme d'une couronne simple de crochets uniformes, 
 generalement en petit nombre, a manche beaucoup plus long que la garde, 
 qui est toujours faible. 
 
 2. Dicranotaenia, pour ceux du type Taenia coronula Dujardin, qui 
 ont une couronne simple de crochets uniformes, courts, generalement en 
 petit nombre, a garde egalant ou supassant egalement le manche en 
 longueur, et formant avec la lame une sorte de petite fourche. 
 
17] STUDIES ON AVIAN SPECIES OF EYMENOLEPIDIDAE—MAYHEW 17 
 
 "Plusieurs autres divisions semblables devront etre effectuees par la 
 suite, mais j'ai vise principalement ici les Teniades des Oiseaux domestiques, 
 les seuls dont j'aie pu jusqu'a, present m'occuper d'une facon suivie." 
 
 Railliet gives no list and mentions no species other than those named 
 as the types. Stiles (1896) recognizes the above genera and groups several 
 species under each with diagnoses of each and a key. The difficulties which 
 are encountered when an attempt is made to use the above characters as 
 distinctive of genera are very evident in Stiles' classification. He includes 
 in the genus Dicranotaenia Amoebotaenia cuneata Linstow 1872 ( = Dicran- 
 otaenia sphenoides) which has 15 to 20 testes and alternating genital pores. 
 Along with the above species he includes H. coronula Dujardin 1845, 
 H. aequabilis Rud. 1809 and H. furcigera (Krabbe) 1869. In the genus 
 Drepanidotaenia, Stiles places Monopylidium infundibulum (Bloch) 1779, 
 which is like Amoebotaenia cuneata in that it has numerous testes. Here 
 also are placed H. tenuirostris (Rud.) 1819, H. setigcra (Frolich) 1789, 
 H. collaris (Batsch) 1786, ( = H. sinnosa Zeder 1800), H. anatina (Krabbe) 
 1869, H. lanceolata (Bloch) 1782, H. fasciculata Ransom 1909 ( = H.fasciata 
 Rud.) 1809, and H. gracilis (Zeder) 1803. It is seen by the classification 
 outlined above that much difficulty is encountered in bringing such widely 
 different forms into the same genera. An interesting note is found in the 
 addendum, (p. 60) of Stiles (1896) as follows: 
 
 "Choanotaenia: Railliet proposes a new genus, with Taenia infundi- 
 buliformis Goeze as type in the following words: Le Taenia infundibali- 
 formis Goeze, que j'avais place provisoirement dans le genre Drepanido- 
 taenia, s'en distingue par le grande nombre des testicules, et d'une maniere 
 generale par la constitution de l'appareil reproducteur (Crety). II merite 
 done de devenir le type d'un nouveau genre Choanotaenia. Ch. infundibuli- 
 formis, intestin de la poule." 
 
 "Although I recognize the great difference in organization between 
 T. infundibuliformis (as described by Crety) and the other species of Taenia 
 which have been placed in Drepanidotaenia, and am inclined to consider 
 it generically distinct from these worms (see p. 45), and although I have 
 the highest regard for the opinion of my colleague and for his keen foresight, 
 particularly in systematic questions, I prefer to reserve judgment upon his 
 new genus until its type species and a few allied forms are more thoroughly 
 understood, especially as it appears to me that T. infundibuliformis as 
 determined by various authors is rather a heterogeneous and collective 
 species." 
 
 Thus it is apparent that uncertainty was at once present in the minds 
 of the first workers in these new groupings as to the importance of the 
 characters which they had assigned to them, when they made comparisons 
 with the internal structures. 
 
 Cohn(1901) divided the genus Hymenolepis into the subgenera Hymeno- 
 lepis, which contained those species with more than ten hooks or with 
 
18 ILLINOIS BIOLOGICAL MONOGRAPHS [18 
 
 rostellum rudimentary and unarmed, and Drepanidotaenia, which included 
 those with eight to ten hooks. Neither of the above subdivisions have 
 come into general use due to the difficulty of accurately dividing a group 
 of species on the basis of the number of hooks or their shape. The difficulty 
 is very real when the shape is used since there are all grades of inter- 
 mediate forms between the two extremes, and such a system would be 
 mathematical, a very unsatisfactory method due to the differences in 
 position in which different observers might select in which to view the 
 hooks, and the errors of measurements of different investigators. It also 
 happens in many cases that the scolex is not obtained or it may not be 
 possible to count the hooks or to observe their shape accurately, due to the 
 state of contraction of the rostellum. If, in such a case, the scolex is 
 sectioned, there is always the possibility that hooks may be torn off by 
 the knife or cut into pieces, leading to an unreliable count and view of the 
 shape. It is not infrequent also that individual hooks are lost, and, if this 
 happens, the fact is sometimes difficult to detect from the position of the 
 remainder. A very striking illustration of the slight value which may be 
 placed upon the characters of the hooks aside from the internal structures 
 is found in Weinlandia introversa and Weinlandia macrostrobilodes. It is 
 noted in the descriptions of these forms that the hooks are almost identical 
 in shape, so similar in fact that one might easily interpret any discrepancies 
 to inability to obtain a proper view; the hooks are also very near to each 
 other in size (W. macrostrobilodes 15 to 16m, and W. introversa 17 to 20m) 
 and number. 
 
 Moreover, the arrangement and general structure of the internal organs 
 are almost identical except for the differences in size recorded in detail in 
 the description of W. introversa. There are two very outstanding differences, 
 however, which separate these two species very widely from each other. 
 These are the differences in the rostellum, which in W. introversa it is an 
 introvert, and in W. macrostrobilodes is retracted as a solid muscular organ, 
 and the difference in the size of the internal organs and of the strobila 
 for the details of which the reader is referred to the descriptions of the 
 species. 
 
 A little discussion of the manner of retraction of the rostellum seems 
 proper at this point. It would appear that if the characteristic difference 
 between the muscular arrangement of the rostellum which results in this 
 organ being retracted as an introvert in the one case, and as a solid muscular 
 organ in the other, had been observed by former investigators, they would 
 have attached as much importance to it as they did to the number and 
 shape of the hooks. The differences in the muscular arrangement are 
 indeed marked as is apparent when figures 63 and 72 are compared. Yet 
 this difference was not fully established until sections were studied; there- 
 after the arrangement could be made out in properly prepared toto mounts. 
 
19] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 19 
 
 Another subdivision of the genus Hymenolepis remains to be discussed. 
 Blanchard (1891) groups the cestodes with armed suckers into three 
 genera, namely: Echinocotyle R. Blanchard 1891, Davainea R. Blanchard 
 and Railliet 1891, and Ophryocotyle St. Friis 1870. The genus Echinocotyle 
 was based upon the anatomy of Echinocotyle rosseteri, the internal antomy 
 of which is imperfectly known, but which had the suckers armed with 
 three series of hooks. But one species was placed in this genus by R. 
 Blanchard; later Fuhrmann (1908) included four others besides the type 
 mentioned above and considered it as only a subgenus. The value of such 
 an external character, however, seems to be of little importance. 
 
 In connection with the study of the scolex and other external features 
 as systematic characters, it is interesting to note the conclusions arrived at 
 by Fuhrmann (1918) as a result of his studies on the anatomy of Fimbriaria 
 intermedia Fuhrmann 1914 and F. fasciolaris (Pallas 1781). The relative 
 importance of the pseudoscolex as compared with the internal structures 
 as a systematic character is very fully considered, and the conclusion is 
 reached that it is of only secondary importance and that the genus should 
 be placed in the family Hymenolepididae. 
 
 Concerning comparative studies upon the species assigned to the genus 
 Hymenolepis, there seems to be few of any importance because of their 
 limited range. Fuhrmann (1906d) compares the hooks as to number and 
 shape in a considerable number of species. On page 625 he gives a diagram 
 showing the relationships between the different shapes, and mentions a 
 number of species in connection with each type. He also discusses in a 
 general way the scolex, excretory system, musculature, and cirrus sac. 
 Fuhrmann (1906e) compares the reproductive organs of a limited number 
 of species by taking into account the relative position of the testes to each 
 other and to the ovary. He defines nine groups which may be described 
 as follows, using the letters designating his figures: 
 
 a, — two testes posterior and one anterior and median to both posterior organs, typical 
 
 species E. megalorchis Llihe 1898, E. microps (Dies.) 1850, E. coronula (Duj.) 1845, 
 
 E. filirostris Wedl. 1856. 
 b, — arrangement like above but anterior testis in front of antiporal posterior, no typical 
 
 species named. 
 c, — arrangement a, except anterior testis is lateral to antiporal posterior testis, typical species 
 
 H.farciminalis (Batsch) 1786, E. interrupta (Rud.) 1809, E. longirostris (Rud) 1809, 
 
 E. megalops (Nitzsch) 1829, E. gracilis (Zeder) 1803. 
 d, — two testes antiporal and one poral to the ovary, in a transverse row, typical species 
 
 E. bisaccata Fuhrmann, E. micrancristrota (Wedl). 
 di, — testes like above but lateral ones outside excretory ducts, typical species, E. multiformis. 
 e, — testes like d, but the middle one dorsal to the ovary, typical of E. himantopodis (Krabbe), 
 
 E.fragilis (Krabbe), E. villosa (Bloch), E. acquabilis (Rud.), E. tenuirostris (Rud.), 
 
 E. brcvianntilata Fuhrmann, and E. microscolecina Fuhrmann. 
 f, — two testes poral to ovary and other antiporal, typical of E. brachycephala. 
 
10 
 
 ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 [20 
 
 g, — all three testes poral to ovary but antiporal one dorsal to ovary, typical of E. setigera 
 (Frohlich), H. unilateralis (Rud.) Fuhrmann, H. elongata Fuhrmann. 
 
 h, — all three testes entirely on the poral side of the ovary, typical species H. lanceolata 
 (Goeze). 
 
 The difficulty in using the above groupings arises in placing the ovary 
 correctly for there are all degrees of variation between some of them, as 
 illustrations of which we may mention H. pauciovata Fuhrmann 1906, 
 H. serrata Fuhrmann 1906, H. bilateralis v. Linstow 1905, and others in 
 which the ovary extends beneath the testes, it often being necessary to 
 use the shell gland or vitelline gland instead of the ovary as the point of 
 decision. While there is some value to the above grouping there is less 
 regularity and it is less clearly defined than when the relative position of 
 the testes is used as a criterion. 
 
 Cohn's Group 1 
 
 ' 
 
 ■ 
 
 
 
 
 
 
 
 1 
 
 
 o 
 o o 
 
 o 
 o o 
 
 
 oo° 
 
 
 OQOO 
 
 
 090 
 
 a 
 
 1 b 
 
 
 1 
 c 
 
 d 
 
 
 di 
 
 
 Gere's Type of D. ligidoidcs 
 
 Cohn's Group 2 
 
 Cohn's Group 3 
 
 &&® 
 
 Gere's Type of 
 D. acquabilis 
 
 O0£3O 
 
 oo©p 
 
 ooo§ 
 
 Gere's Type ol 
 D. lanceolata 
 
 TEXTFIGURE 1. DIAGRAM SHOWING THE RELATION BETWEEN THE 
 
 GROUPINGS OF SPECIES OF HYMENOLEPIS MADE BY 
 
 FUHRMANN, COHN AND CLERC 
 
 (The figures are after the patterns made by Fuhrmann) 
 
 Clerc (1903: 308) distinguishes three types of testicular arrangement, 
 based partly upon other observers' work in the subgenus Drepanidotaenia 
 which he designates as follows: 
 
 a, — type of D. Hguloides. "Le premier type a ete deja decrit par Cohn. II est caracteristique 
 pour les especes a proglottis relativement long, ce qui permet a un des testicules de se 
 loger en avant de l'autre." 
 
 b, — type of D. lanceolata, "etabli par Wolffhiigel et par Cohn, ne renferme que deux especes, 
 D. lanceolata et setigera, que j'ai decrites plus haut. II est caracterise' avant tout par le 
 fait que les glandes femelles sont tres peu volumineuses et entierement logces dans la 
 moitie du proglottis oppesee au pore genital. Les testicules sont, par contre, tres volum- 
 ineux et disposes suivant une ligne transversale." 
 
21] STUDIES ON AVIAN SPECIES OF EYMENOLEPIDIDAE—MAYHEW 21 
 
 c, — type D. acquaints, "comme les deux types precedents, caracteris£ par un tres grand 
 developpement des testicules, mais il en difftre par la position et les dimensions des 
 glandes femelles. Ces dernieres sont medianes, rigoureusement ventrales et occupent 
 souvent tout le champ ventral du proglottis, entre les vaisseux excreteurs." 
 
 Cohn (1904) in a footnote (p. 244, 245) discusses the arrangement made 
 by Clerc and described above, and defines these three groups as follows: 
 
 1. Hoden inkongruent, einer proximal, zwei distal. Weibliche Driisen wenig in die Breite 
 entwickelt, mehr-weniger median. 
 
 2. Alle drei Hoden auf einer Seite, wahrend die weiblichen Driisen auf der anderen Seite 
 liegen. 
 
 3. Hoden kongruent, einer median. Weibliche Driisen stark in die Breite entwickelt. 
 
 This, it is seen, is but little different from that outlined by Clerc except 
 that the ovary enters into all three, while Clerc leaves it out of account 
 in the D. liguloides type. The diagram in textfigure 1 indicates the relation- 
 ships between these three suggested groupings. 
 
 GENUS DIORCHIS CLERC 1903 
 
 This genus is relatively young and consequently one finds few historical 
 data. It was established by Clerc (1903: 281) with D. acuminata as the 
 type. He defined its characters as follows: 
 
 "Cestodes d'oiseaux a proglottis tres nombreux et courts. Crochets du rostellum en 
 petit nombre et en couronne simple. 
 
 "Pores genitaux unilateraux. Deux testicules par proglottis. Muscles longitudinaux 
 divises en deux couches, dont l'interne ne comprend que huit faisceaux. 
 
 "L'uterus sacciforme remplit tout le proglottis mur." 
 
 Fuhrmann (1906e: 738) places the genus Diorchis in its present group 
 of genera saying as follows: 
 
 "Das Genus Hymenolepis bildet mit den Genera Aploparaksis Clerc, Diorchis Clerc und 
 Oligorchis Fuhrmann eine sehr natiirliche Gruppe, welche manchen gemeinsamen Zug in der 
 Art der Bewaffnung und der Anatomie zeigt und deshalb sehr wohl eine besondere Unter- 
 familie der Cyclophylliden zu bilden berechtigt ist." 
 
 In the next paragraph Fuhrmann gives a diagnosis and names the 
 subfamily Hymenolepinae. In 1908 he places these four genera in the 
 Hymenolepididae. Ransom (1909) places these four genera in the sub- 
 family Hymenolepidinae giving a diagnosis and list of species with refer- 
 ences to their descriptions. 
 
 GENUS HAPLOPARAXIS (CLERC) 1903 
 
 The genus was first set up by Clerc (1902a) under the name of Monor- 
 chis to contain those species of cestodes which possessed but one testis in 
 a proglottid. In 1903 he displaced the name Monorchis with Aploparaksis* 
 
 ' The name should be spelled Haploparaxis. 
 
22 ILLINOIS BIOLOGICAL MONOGRAPHS [22 
 
 since he had found that the former had already been given to two species of 
 trematodes. In the preliminary report Clerc includes six species as follows: 
 H. filutn, as tpye, H. crassirostris, H. hirsuta, H. cirrosa, H. dujardini, 
 and a variety of H. filum, viz: pseudofilum, which he described as a new 
 species. In the complete report of 1903, Clerc describes an additional 
 new species H. penetrans, and reduces his former new species, pseudofilum, 
 to a variety of H. filum. The complete list of species now placed in this 
 genus appears in the systematic section of this paper, as well as a diagnosis 
 of the genus. 
 
23] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 23 
 
 PROPOSED REVISION OF THE GENUS HYMENOLEPIS 
 
 As the information concerning the anatomy of the various species of 
 Hymenolepis was brought together for comparison, it soon became appar- 
 ent that the testes were usually the most satisfactorily described of the 
 internal organs. Their position was usually stated, and, in a large per- 
 centage of cases, figured. This fact suggested the possibility of arranging 
 a number of groups of species which might be made use of in constructing 
 a key. As a further indication of the usefulness and the reliability of such 
 groupings, it was noted, when a study of the material collected was under- 
 taken, that the testes were invariably characterized by the same relative 
 positions with reference to each other in all the proglottids of a strobila, 
 and likewise, in other specimens of the same species. The few exceptions 
 which may be found, and some are usually found, may be construed as 
 abnormal or unusual, and as suggestive of the condition in the primitive 
 ancestral forms of the group. This point is well illustrated by Weinlandia 
 lateralis which has two testes placed on the posterior border and the third 
 in front of and lateral to the antiporal posterior organ. The ovary is located 
 behind and lateral to the anterior antiporal and lateral to the posterior 
 antiporal testes, as is shown in figure 54. This position is characterized by 
 its extreme regularity; not a single variation has been noticed. In the young 
 proglottids where the early conditions are first visible, the testes are so 
 placed, which indicates that these are the positions where the testes are 
 fundamentally located, and that they are not pushed into it by the pressure 
 of the very large cirrus sac and the ovary, even when these organs are fully 
 developed. 
 
 Species with the testes in a transverse row are the most constant with 
 respect to the position of the testes. As examples of this may be mentioned 
 Hymenolepis lobulata and Hymenolepis ciineata which have two testes on 
 the poral side of the ovary and vitelline gland and one on the antiporal. 
 The most outstanding exception to this is Hymenolepis sacciperum in which 
 the testes are arranged two antiporal and one poral in about 95 per cent of 
 the proglottids, while in the remainder either the arrangement differs 
 from this or the number is other than three. This case is discussed more in 
 detail later and an explanation offered for each of these irregularities. In 
 a general way it may be stated at this point that they are believed to 
 indicate the ancestral condition of the group, and that the various types 
 of testicular arrangement found in the present species have developed 
 from a primitive form with no fixed arrangement. A further point of 
 interest is that among the species which do not have the testes arranged 
 
24 ILLINOIS BIOLOGICAL MONOGRAPHS [24 
 
 in the same manner in all the proglottids of the strobila, there are some 
 which have a very variable pattern, as does Wardium variabile, while in 
 Weinlandia microcirrosa the variability is restricted within certain limits. 
 In the latter, two of the testes are always posterior and the third anterior 
 to the antiporal testis, but may be either medial, lateral, or directly 
 anterior to it. In this species the arrangement is considered to be sufficiently 
 limited to be included in the genus Weinlandia, which is characterized by 
 having two testes posterior and one anterior to the antiporal testes. In 
 other words, from a phylogenetic standpoint, the species has become 
 sufficiently stable in its arrangement to indicate to what group of species 
 it is the most closely related. 
 
 In the study of the anatomy of the species collected from American 
 birds, several morphological details have been found which indicate that 
 the testes of the species of Hymenolepis are compound organs. A discussion 
 of these data is given in the following pages and under the following 
 headings: (1) the irregularity in the number and branching of the vasa 
 efferentia, (2) the lobing of the testes, and (3) the number and irregularity 
 in position of the testes in Hymenolepis sacciperium. 
 
 Early in the comparative study of the species, the arrangement of the 
 vasa efferentia suggested a possible relationship between the testes. As an 
 illustration, in Hymenolepis cuneata (Fig. 50) the ducts from the two poral 
 testes join and then their common duct unites with the one from the 
 antiporal testes to form the vas deferens. In a species which had two testes 
 poral and one antiporal, if the ducts from the posterior organs joined first, 
 it would indicate that the anterior testis was homologus with the antiporal 
 testis in Hymenolepis cuneata and would belong to the same natural group. 
 As a result of this, the different patterns of testes arrangements maybe 
 considered to have risen through a rearrangement of that pattern found in 
 the primitive form. As an illustration, Ransom (1902) gives a figure of the 
 arrangement in Hymenolepis megalops (Fig. 15) in which the two antiporal 
 ducts joint before uniting with the poral duct. To correlate this with the 
 arrangement found in H. cuneata, the two poral testes would have to be 
 shifted to the antiporal position, a seemingly impossible rearrangement, 
 and indicating that these two species would belong to different natural 
 divisions. A very real difficulty was at once encountered in the literature 
 since there are only about seven descriptions of species in which there is any 
 reference to the manner of union of the vasa efferentia; most of these are 
 noted only in figures, and no statistical records of any sort given as to their 
 regularity. Upon these grounds, it would be impossible to secure enough 
 data to make anything like a satisfactory arrangement of such an exceed- 
 ingly large number of species in a key by means of which one would be able 
 to classify a cestode of this genus which he might have. 
 
 The study of the vasa efferentia in the material available revealed 
 some interesting facts concerning which a rather detailed discussion of 
 
25] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 25 
 
 several species seems now advisable. In W einlandia microcirrosa (Fig. 1) 
 there were found in four consecutive proglottids, which were examined in 
 frontal section, all of the possible patterns of union of the vasa effer- 
 entia. In figure la the ducts from the two posterior testes join first, in 
 lb and lc, the ducts from the two antiporal join first, while in Id all three 
 join at the same point. In W einlandia macrostrobilodes one of the seven 
 proglottids of which the arrangements are represented in figure 2e, has the 
 ducts from the three testes all joining at the same point, while in all the 
 others figured those from the two antiporal testes join first. 
 
 In some proglottids, more than one duct from a testis has been observed. 
 These may unite and their common duct join that from another testis, 
 as they do in figure lc, or they may remain separate as in figure 4c. If it 
 be assumed that the testes of Hymenolepis have been reduced in number 
 from, say six in the ancestral form to three in the present types by the 
 uniting of testes, it seems possible that the ducts have also united or that 
 some of the primitive ducts have persisted and others have not. It is 
 possible upon this basis to explain the diversity of pattern in species which 
 probably have a constant pattern. Take as an illustration the pattern 
 shown in figure 4c; if ducts Nos. 1 and 2 should fuse, retaining the position 
 of No. 1, or that 2 should fail to develop, it would give the pattern found 
 in figure 4a, while if, on the other hand, No. 2 became the functional duct, 
 the result would be the pattern shown in figures Id and 2e. Some of the 
 patterns show considerable evidence for the fusion of the ducts, as for 
 example, figure 4b, where there are two ducts from the poral testis, with a 
 cross connection between them. If in this instance the posterior antiporal 
 testis is a compound structure made up of three simple organs, each 
 originally with a single duct, and the present single duct from it made up 
 of the three primitive ducts and the poral testis made up of two simple 
 organs, one can readily determine the original pattern. Another interesting 
 pattern in this connection is that shown in figure 3e, which indicates that 
 the single duct from the anterior antiporal testis is made up of three ducts 
 or that it contains two and the single duct from the antiporal posterior 
 testis contains two, either of which would result in the pattern shown. 
 Figure 3d is suggestive of the union of the ducts from two testes resulting 
 in a different pattern. If these had remained separate as far up as is 
 indicated, the result would be a pattern similar to that found in figure 2e, 
 where all the ducts join at the same point, or if the vas deferens had 
 remained simple as far up as the opening between its two portions, the 
 arrangement would be like in figure 4a. An examination of the exceedingly 
 complex patterns shown in figures 6, 10, and 11 reveals the fact that any 
 pattern can be obtained by considering that the testes are compound and 
 that their ducts are formed by the union of the primitive ducts or by the 
 failure to retain some of the primitive ducts. 
 
26 ILLINOIS BIOLOGICAL MONOGRAPHS [26 
 
 Reference has been made above to the probable number of testes which 
 have entered into that organ in the present condition, namely that there 
 is a possibility of three in the anterior antiporal testis in figure 3e, or two 
 in both the antiporal testes on a basis of the arrangement of the ducts. 
 Several proglottids have two distinct ducts to a testis, namely figures 2a, 
 b, f, 4c, and several in the proglottids figured from Weinlandia planestici, 
 as in figures 6, 10, and 11. Three instances are shown in figure 6 of a testis 
 having three ducts, and one in figure 2c. The evidence for a larger number 
 of testes entering into that organ of present forms rests on Fig. 2d, which 
 shows four ducts attached to the anterior antiporal testis. 
 
 A further indication of the compound nature of the testes is to be found 
 in their being lobed. These organs are found to be regularly lobed in 
 Weinlandia macro sir obilodes and Weinlandia introversa. The most interest- 
 ing species, however, in this connection is Eymenolepis sacciperiiim, which is 
 further characterized by the unusual variability in the number of testes 
 discussed at length in the next paragraph. It is not uncommon for the 
 testes to be lobed or constricted anterioposteriorly as is shown in proglottids 
 in figure 44. Those which have but two testes, one on each side of the 
 ovary, as is found in Fig. 44h, can be explained by considering that the 
 two testes on either side in proglottid e have united and the constriction 
 indicates the plane of fusion. Proglottid i indicates that the two on the 
 poral side only have joined and j suggests that the two adjacent to the 
 ovary on the antiporal side have fused. An interesting fact in this connec- 
 tion is that no testis was observed which had a constriction that did not 
 have it directed along the anterioposterior axis of the strobila. These 
 testes were studied in sections and found to be single organs and not to 
 be due to separate organs overlapping one another, which would give this 
 effect in toto mounts. Unfortunately in this species, the vasa efferentia 
 were so poorly defined and lay so close to the testes that they could not be 
 traced with any degree of certainty beyond the region of the vas deferens. 
 The arrangements of the ducts indicated in figure 5 have some interesting 
 irregularities and are suggestive of fusion of the ducts and testes. 
 
 The number of testes found in the proglottid also is another indication 
 that there is a change taking place in the number of testes in this group of 
 cestodes. It is only occasional that one finds a number other than three, 
 but one does find in almost any species proglottids with one, two, and four 
 testes in a proglottid. One of the species studied, however, is interesting in 
 this respect. A careful examination of almost 1400 proglottids in two 
 specimens of Hymenolepia saccipcrium showed that in one specimen 5 per 
 cent and in the other 7 per cent of the total in each possessed a number 
 other than three or an arrangement other than that typical for the species. 
 A representative figure of each of these types of arrangements is shown 
 in figure 44. Of the total number, 1307 had the typical arrangement shown 
 
27] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 27 
 
 in i and j or two testes antiporalandone poral to the ovary. The numbers 
 of each of the other types found are as follows: of the type shown in 
 proglottid c 29, d 8, e 5, f 20, g 16, and b, only 2. 
 
 It is now necessary to discuss some of these conditions in order to see 
 how they may have come about. The presence of one testis on each side 
 of the ovary has been referred to above as being possible through a fusion 
 of two testes in each of these respective positions. The relative size 
 of the testes is often evident as where there is only one it is invariably much 
 larger than either of those where there are two. The lobing or constrictions 
 in these organs in the anterioposterior axis has been referred to above and 
 is frequently evident. The arrangements where there are two on either 
 side of the ovary or two on the poral side and one on the antiporal may be 
 explained on the basis that either fusion has or has not taken place in that 
 location. The fact that so many proglottids (20) were found which contain 
 but two testes on the antiporal side is believed to be an indication that 
 this species is still somewhat unstable and shows some relation to another 
 group of species containing only two testes. This may have occurred by 
 fusion or by a failure of the poral testis to develop. Indeed, one sometimes 
 finds groups of cells in the position of the poral testis which stain weakly 
 in a manner similar to those in the testes and these undoubtedly are 
 reproductive cells. 
 
 The evidence presented above indicates that each of the three testes 
 of the species assigned to the genus Hymenolepis has been formed phylo- 
 genetically by the fusion of at least four simple testes. This has been 
 presented under the following headings: (1) number and irregularity in 
 the arrangement of the vasa efferentia; (2) lobing of the testes, and (3) the 
 irregularities in the number and arrangement of the testes in Hymenolepis 
 sacciperium. 
 
 There is considerable basis for believing that the evidence presented 
 above does not indicate a splitting in the testes rather than a union. In 
 first place, the ducts are found to be irregular in the youngest proglottids 
 in which they can be recognized indicating that the irregularities are 
 present from the beginning of their development. There is no increasing 
 complexity in the vasa efferentia in proglottids in an anterio-posterior 
 series. Again, the testes, as compared with the ducts, may be said to be 
 physiologically the most active, and if splitting were taking place the 
 testes would be already divided or lobed, and the duct divided only 
 nearest the testes. The contrary is found to be the case when the figures 
 are examined, as for example in figure 2f the two ducts from the anterior 
 testis approach very near to each other at the testis but are widely separ- 
 ated at their opposite ends. A similar arrangement is to be observed in 
 figure 2a, b, d, and 3e. In the third place, more than one vas efferens may 
 connect with a lobe of the testis and with no regularity of position on the 
 
28 ILLINOIS BIOLOGICAL MONOGRAPHS [28 
 
 lobe. This is the condition to be expected since the lobing of the testes 
 would probably disappear before the complete union of the ducts. In the 
 fourth place, considered from a phylogenetic standpoint, the most highly 
 developed group of cestodes might be expected to be found in the most 
 highly developed hosts. The occurrence of the members of the Hymeno- 
 lepididae in birds and mammals is in support of the conclusion that the 
 testes are compound since the cestodes parasitic in lower animals have more 
 numerous testes. 
 
29] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 29 
 
 PHYLOGENY OF SPECIES IN THE GENUS HYMENOLEPIS 
 
 It is believed that the compound nature of the testes discussed in the 
 preceding section has a direct bearing upon the relationships of the various 
 groups of species which are to be made in the following section. An attempt 
 was made in the last section to show that the three testes found in the 
 present species is the result of the fusion of several simple organs present 
 in primitive forms. 
 
 Another characteristic, which has not been referred to as yet, and which 
 is believed to be very important, is the position of the pore and the relation 
 of the genital ducts to the longitudinal excretory canals. An outstanding 
 fact is that the genital ducts are always dorsal to the longitudinal excretory 
 canals in all the species studied and in all the proglottids. This fact is not 
 so difficult to determine as it might appear for in many species it can be 
 very readily ascertained from toto mounts by careful focusing with a high 
 power lens. This depends, however, upon the nature of the cirrus sac and 
 the excretory canal. If they are both small and he close together, it is 
 sometimes impossible to determine this point with certainty from a toto 
 mount and sections then become necessary. This point has been carefully 
 studied in all the species, and in several specimens of each where such a 
 number was available, and not a single exception was found. In young 
 proglottids the position of the earliest stage of the cirrus sac is dorsal to 
 the excretory ducts. But three exceptions have been described which have 
 come to the notice of the writer. E. asymetrica Fuhrmann 1918 has the 
 genital ducts regularly passing above, but exceptionally they may pass 
 between the excretory ducts. H. spinosa Linstow 1906 is described as 
 having the genital ducts passing between the excretory ducts, and H. clausa 
 Linstow 1906 has the cirrus sac above and the vagina ventral, the two 
 merging and the pore being absent. A careful restudy of these species 
 should be made with the view to determining the constancy and the 
 importance of these facts. It may be that these are representative of distinct 
 groups to which others of the incompletely studied species may belong. 
 
 The regularity of the unilateral position of the genital pores has been 
 referred to above, and the fact noted that but one exception has been 
 observed, that of two proglottids in one specimen of W einlandia lateralis 
 having the pores on the opposite side from all the other proglottids in the 
 specimen. It is believed that the regularity in position of the genital pores 
 and genital ducts with reference to the excretory ducts is a very important 
 morphological character which should be carefully determined in the 
 future study of these forms. 
 
30 ILLINOIS BIOLOGICAL MONOGRAPHS [30 
 
 It is now possible to formulate a conception of the ancestral form from 
 which the various species assigned to the genus Hymenolepis have been 
 derived. At least six testes and as many as twelve were present in a 
 proglottid since the evidence presented above shows that at least two 
 and possibly as many as four have joined to form a single testis of the 
 present species. These testes had no definite pattern in the various pro- 
 glottids of the strobila. The genital pores also alternated from side to side 
 and the genital ducts were to be found dorsal, ventral or between the 
 longitudinal excretory ducts. The first forms with fixed characters which 
 diverged from this most probably had the genital ducts dorsal to the 
 excretory canals and the pores unilateral. The most distinctive morpho- 
 logical character next to appear probably was in connection with the testes. 
 It seems quite possible that the several testes first became localized in 
 groups in definite locations in the proglottid. As an illustration, let us 
 assume that there were twelve testes and that these became localized 
 along the posterior border of the proglottid in groups of 4 or that two groups 
 came to be found along the posterior border and the other in front of the 
 posterior antiporal group. The next stage was seen in the union of these 
 testes in those respective positions. In this manner it becomes apparent 
 that the groups of species which have similar patterns of testes arrangement 
 are fundamentally related, and that this relationship goes back to their 
 common origin. They are thus separated from the species having other 
 arrangements in a distinct and peculiar manner. The study of material 
 and of descriptions reveals one group of species which have the testes 
 arranged in an irregular manner. In the development of this group it may 
 be assumed that the position of the groups of testes in the ancestral form 
 did not become stabilized as to position in the proglottid, consequently 
 when union took place, the compound organ retained this characteristic, 
 and this group of present day species presents a variable pattern of testes 
 arrangement. 
 
 Upon the basis of the above observations the author believes that the 
 pattern of the testes arrangement is sufficiently reliable, easily enough 
 ascertained, and goes back far enough in the phylogeny of the group to 
 constitute a generic character. The position of the ovary in the proglottid 
 and with reference to the testes at first seemed to be important, but it 
 soon became apparent that this was much less clear cut and well defined 
 since it usually overlaps the testes and sometimes it was necessary to use 
 the position of the vitelline gland instead. This point is discussed more at 
 length in the section on the history of the genus. 
 
 The following diagram (Textfig. 2) is believed to represent the relation- 
 ships set forth above among the species which have been assigned to 
 this genus. 
 
31] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 31 
 
 TEXTFIGURE 2. DIAGRAM SHOWING THE PHYLOGEXETIC RELATION- 
 SHIPS BETWEEN THE GENERA WARDIUM, HVMENOLEPIS, 
 AND WEINLANDIA. 
 
 Wardium 
 
 Hymcnolepis 
 
 Weinlandia 
 
 Testes 3 
 position 
 variable 
 
 Testes 
 
 variable 
 
 in no. and 
 
 position 
 
 Pores unilateral 
 
 Testes variable in number and position 
 
 Genital ducts dorsal to excretorv vessels 
 
 Primitive Form 
 Pores irregularly alternating 
 Testes variable in number and position 
 Genital ducts dorsal, \entral or between excretory vessels 
 
32 ILLINOIS BIOLOGICAL MONOGRAPHS [32 
 
 KEY TO SUBFAMILIES AND GENERA OF FAMILY HYMENOLEPIDIDAE 
 
 1(2) Four testes in each proglottid 
 
 Subfamily Oligorchinae Oligorchis 
 
 2(10) Three testes in each proglottid 
 
 Subfamily Hymenolepidinae 3 
 
 3(7) Excretory vessels 4 in number, the genital ducts probably always passing 
 dorsal to them. Scolex well developed. No pseudoscolex. Rostellum an 
 introvert, not an introvert, or rudimentary, and armed with a single or 
 
 double crown of hooks or unarmed 4 
 
 4(5) Position of the testes variable Wardium 
 
 5(6) Testes in a transverse row Hymenolepis 
 
 6(7) Two testes posterior, the third anterior to the posterior antiporal testis 
 
 Weinlandia 
 
 7(3,8) Excretory vessels 4 in number. The genital ducts pass between thelongi- 
 
 tudinal excretory vessels. Longitudinal muscle bundles in two layers. 
 
 Scolex well developed. Rostellum proboscis-like, with hooks distributed 
 
 over its surface. Strobila well marked off into proglottids 
 
 Echinorhynochotaenia 
 8(3,9) Excretory vessels 10 in number. Longitudinal muscle bundles in a single layer. 
 Strobila well marked off into proglottids. Scolex well developed. Rostel- 
 lum armed with a single crown of hooks Hymenofimbria 
 9(3,10) Longitudinal excretory vessels 3 to 11 in number. Scolex small. Pseudoscolex 
 present. Strobila not marked off into distinct proglottids 
 
 Fimbriaria 
 10(11,1) Two testes in each proglottid 
 
 Subfamily Diorchinae Diorchis 
 
 11(1) . One testes in each proglottid 
 
 Subfamily Haploparaxinae Haploparaxis 
 
33] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYBEW 33 
 
 FAMILY HYMENOLEPIDIDAE (ARIOLA) 1899 
 
 Family diagnosis: Cestodes with regularly from one to four testes in 
 each proglottid. Rostellum either unarmed or armed with a single or double 
 crown of hooks. Rarely the hooks are distributed over the surface of the 
 rostellum. Genital pores unilateral. The uterus usually sac-like. Pro- 
 glottids usually broader than long. Longitudinal muscle bundles in one or 
 two layers. 
 
 Type genus: Hymenolepis Weinland 1858 
 
 The names of hosts of previously described species used in this paper 
 are in agreement with the references cited, those of new species were 
 obtained from the A. O. U. Check-list of 1910. 
 
 It should be indicated at this point that, due to the inadequate descrip- 
 tions of many of the species, a number have been placed in the genera from 
 the genus Hymenolepis with considerable doubt as to their relationship, 
 and that before a final determination is made of any new material the 
 original description should be consulted. 
 
 SUBFAMILY OLIGORCHINAE 
 
 Subfamily diagnosis: Hymenolepididae having regularly four testes 
 in each proglottid. 
 
 Type genus: Oligorchis Fuhrmann 1906 
 
 GENUS OLIGORCHIS FUHRMANN 1906 
 
 Generic diagnosis: Four testes in a proglottid. A single set of repro- 
 ductive organs in a proglottid. Genital pores unilateral, marginal or 
 dorsal in position. Genital ducts pass dorsal to the longitudinal excretory 
 vessels. Rostellum armed with a single crown of hooks. 
 
 Type species: Oligorchis strangulahcs Fuhrmann 1906 
 
 OLIGORCHIS STRANGULATUS FUHRMANN 1906 
 
 Fuhrmann 1906a: 217-218 (Fig. 26-29). 
 Host: Elanoides f meatus (L.). 
 Locality: Brazil. 
 
 Length 10 cm. Width 1 mm. Hooks 14 to 16, 34ju long. Ovary and 
 vitellaria median, the former but slightly lobed. Testes irregular in position. 
 Proglottids much wider than long. 
 
34 ILLINOIS BIOLOGICAL MONOGRAPHS [34 
 
 OLIGORCHIS DELACHAUXI FUHRMANN 1909 
 
 Fuhrmann 1909: 29 (Figs. 36-37). 
 Host: Phalacrocorax africanus (Gm.). 
 Locality: Egypt. 
 
 Scolex absent. Position of testes variable. Female sex glands not well 
 developed, but are on the poral side of the proglottid. Cirrus sac reaches 
 beyond the excretory vessels, its greatest diameter being at the poral end. 
 Vagina is straight with seminal receptacle on its inner end. Proglottids 
 appear from figure 36 to be much wider than long. 
 
 OLIGORCHIS YORKEI (KOTLAN) 1923 
 
 Synonym: Dilcpis yorkci Kotlan 1923. 
 Kotlan 1923: 59-63, (Figs. 1-4). 
 Host: Megapodius briinneivettlris Mey. 
 Locality : Friedrich-Wilhelmshafen. 
 
 Length 15 to 20 mm. Mature proglottids 0.2 to 0.4 mm in width and 
 0.05 to 0.1 mm in length. Gravid proglottids are 0.3 to 0.5 mm in width. 
 Rostellum armed with from 50 to 52 hooks in a double crown. The hooks 
 of the anterior row are 135jk and those of the posterior row 148 to 151/x in 
 length. Male and female reproductive organs median in position. Genital 
 pores unilateral. Vagina short, narrow, and provided with a large recep- 
 taculum seminis. Ovary consists of 4 rounded or oval sacs, 1 in the poral 
 half and 3 in the antiporal half of the proglottid, joined by thin walled 
 canals which uniting form the oviduct. Uterus a thin walled sac, the wall 
 of which atrophies in the posterior proglottids. 
 
 The internal structure of this cestode indicates its close relationship 
 to those species already assigned to the genus Oligorchis. The double crown 
 of hooks is not believed to be a character of sufficient importance to exclude 
 it from the family Hymenolepididae. The constancy of the number of the 
 testes in the numerous species of the several genera of the family is such 
 an outstanding characteristic that it serves to separate this group of genera 
 from other genera in a distinct and peculiar manner. 
 
 OLIGORCHIS LONGIVAGINOSUS N. SP. 
 [Figs. 12-16] 
 
 The material which formed the basis of the following description was 
 taken from the large intestine of Pelecanus erythrorhynchos, the white 
 pelican in Yellowstone National Park, Wyoming, on August 10, 1917. 
 Cotypes were deposited in the Ward collection, comprising five toto 
 mounts and four sets of serial sections, catalogue numbers 25.22, and 
 25.23. For the most part the specimens are only fairly well fixed so that 
 some of the details, such as vasa efferentia, could not be made out. 
 
35] STUDIES ON AVIAN SPECIES OF EYMENOLEPIDIDAE—MAYEEW 35 
 
 The specimens vary in length from 15 mm to 60 mm and in maximum 
 width from 0.5 to 0.8 mm, according to the stage of sexual maturity and 
 the condition of contraction of the worms when fixed. The width just 
 behind the scolex is about 175-200/*, while in the region where the male and 
 female reproductive organs are well developed, it is about 500/* and in the 
 posterior portion where the uterus is fully distended, somewhat narrower, 
 about 350/*. 
 
 The scolex (Fig. 13) is a conspicuous portion of the worm, having a 
 width up to almost 0.6 mm and a length of about 0.4 mm. The rostellum 
 is strongly developed, being about 200/t wide and about 100/* long. The 
 rostellum has, apparently, a single crown of large hooks the shape of which 
 is indicated in figure 16. They are 88 to 92/* long, and about 20 in number 
 on one rostellum, which was retracted so that an accurate count could not 
 be made. Another unretracted rostellum had 10 and another 12, both of 
 which showed evidence of having lost hooks since those still remaining 
 were twisted out of a regular arrangement, and on one side of one there 
 were five set closely together, while on the other there was but one. An 
 examination of the retracted rostellum appears to show a double crown of 
 hooks, but when examined more closely, it seems quite evident that this 
 is due to the position of the bases of the hooks when retracted. The blades 
 of the hooks are directed outward showing that the rostellum is an introvert 
 and the points of the hooks are observed to be in two rows. When the 
 position of the dorsal root of the bases is examined, it is seen that those 
 of the hooks of the posterior row are inside those of the anterior row which 
 would result in the blade being carried farther outward than in the case 
 of the anterior row. This difference in position of the points together with 
 the fact that the scolex is tilted somewhat so that an exact lateral view is 
 not obtained, would account for the appearance of two rows of hooks. An 
 unretracted rostellum with a full complement of hooks would be conclusive 
 proof of the exact arrangement but such is not at hand, and there is little 
 probability of gaining more data by sectioning the one now under con- 
 sideration. The general form, size, muscular arrangement, and structure 
 of the proglottids agree with that of the other scolices and proglottids so 
 that there is no doubt that they are all of the same species. There was no 
 evidence of a double crown in any of the unretracted specimens, and, while 
 the case is not clear, the probability is that there is but a single crown. 
 
 The testes are usually four in number but have no regularity of position. 
 They are generally spherical in shape and dorsal in position in the center 
 or posterior portion of the proglottid. Occasionally one is found beneath 
 a lobe of the ovary. The position indicated in figure 15 is a little more 
 common, but they may be in any position with reference to each other, 
 dorso-ventrally as well as laterally. Figure 14 shows their location in 
 three consecutive proglottids. The number of the testes varies slightly 
 
36 ILLINOIS BIOLOGICAL MONOGRAPHS [36 
 
 since in a count in 106 proglottids from 3 specimens, 99 were found to 
 possess four testes, four had three, and one seemed to have five. The size 
 varies considerably, occasionally one is observed one-half or two-thirds the 
 size of the others in the proglottid. The cirrus sac reaches about half way 
 across the proglottid, and gradually increases in size toward the inner end. 
 It contains a small seminal vesicle and a large conspicuous cirrus. The 
 latter extends the full length of the sac in a direct course, bends at the 
 inner end and shortly connects with the internal seminal vesicle. The cirrus 
 is large and conspicuous, being protruded in most of the proglottids of the 
 strobila. Due to the poor fixation of the material, the vas deferens and 
 vasa efferentia were not found, therefore no statement can be made con- 
 cerning the existence of an external seminal vesicle. 
 
 The ovary (Fig. 15) is centrally located, usually a little anterior to the 
 testes and ventral to them in position. It is usually divided into from four 
 to six lobes which are rounded and knob-like at their distal end„. The 
 vitelline gland is a spherical or oval structure, dorsal to the central narrow 
 portion of the ovary and without lobes. The vagina is unusually long, 
 extending from the pore across the proglottid to the excretory ducts of 
 the antiporal side and back again usually to the region of the pore, then 
 across again to antiporal excretory duct and medially and posteriorly to 
 the region of the ovary. The inner end enlarges to form a seminal receptacle 
 which is conspicuous in the advanced stages of sexual maturity. The vagina 
 opens into the shallow genital atrium ventral to the cirrus sac. 
 
 The position of the pore is not marginal but slightly dorsal on the left 
 hand side of the proglottid, at about the junction of the anterior one-third 
 and posterior two-thirds of the proglottid. It was noted that the pore 
 seemed to change from side to side occasionally, but in no instance could 
 this be positively determined since there were always at least two pro- 
 glottids in which the pore or cirrus could not be located between the regions 
 of change. In order to find out the exact structure at one of these points, 
 one of these regions was sectioned. It was found that the muscles showed 
 a twist of the whole chain and that the pores could be traced in a symmet- 
 rical row across the side of the strobila in the proglottids between those 
 where it was on one side and those in which it was on the opposite side. 
 This shows that there has been a twisting of the strobila in the process of 
 fixation. The position of the ovary and testes ventrally and dorsally can 
 be determined in toto mounts on the two sides of these regions and it is 
 found that the pore is on the left hand side in each case. 
 
 The longitudinal muscles are poorly developed, and can scarcely be 
 said to consist of two layers. Although the bundles are scattered dorso- 
 ventrally, they are all about the same size. The longitudinal excretory 
 vessels are four in number, and located near the lateral border of the 
 proglottid. They are about the same size, and vary in position, being 
 
37] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 37 
 
 pushed ventrally on the poral side by the cirrus sac, and turned somewhat 
 laterally in places. The genital ducts always pass above the excretory 
 vessels. 
 
 Of the species which have previously been described as having regularly 
 four testes, Oligorchis yorkei (Kotlan) 1923, having two rows of hooks, 
 approaches the nearest in general structure to the one described above. 
 The most outstanding difference is in the nature of the ovary. In 0. yorkei 
 it consists of four separate sacs, one poral and two antiporal, connected 
 by slender ducts uniting to form the oviduct, while in the above described 
 form it consists of from four to six lobes with knob-like enlargements at 
 the ends. The vagina is short in O. yorkei while in our species it is very long, 
 and the cirrus sac is long and rather narrow and coiled, while in the latter 
 it is short and bulb-like. The hooks also are different in that they are 50 
 to 52 in number in two rows and 135 to 151/x in length, in contrast to about 
 20 in number and 88 to 92^ in the above described form. The other three 
 species described as having four testes are all so different in internal 
 structure that it seems unnecessary to discuss them in detail. 
 
 DOUBTFUL SPECIES 
 OLIGORCHIS PAUCITESTICULATUS FUHRMANN 1913 
 
 Fuhrmann 1913: 17 (Fig. 8). 
 
 This species has from 7 to 11 testes, but Fuhrmann placed it in the 
 genus Oligorchis because of the presence of an external and internal seminal 
 vesicle and revised his original description of the genus accordingly. 
 However, the small and constant number of testes is such an outstanding 
 characteristic of the numerous species of the family Hymenolepididae that 
 it seems that this species should be excluded. The external and internal 
 seminal vesicles, while they are very common and probably almost uni- 
 versal in the family, cannot be considered as anything else but a widened 
 portion of the vas deferens, and are found in all degrees of relative size. 
 They may serve as specific characters but seem scarcely of sufficient 
 importance to cause the modification of generic and family diagnoses to 
 admit species with other more evident unrelated characteristics. 
 
 SUBFAMILY HYMENOLEPIDIDAE (pERRIEe) 1897 RANSOM 1909 (EMENDED) 
 
 Subfamily diagnosis: Hymenolepididae with regularly three testes in 
 each proglottid. 
 
 Type genus: Hymenolepis Weinland 1858. 
 
38 ILLINOIS BIOLOGICAL MONOGRAPHS [38 
 
 
 GENUS HYMENOLEPIS WEINLAND 1858 
 
 Three testes in a transverse row. Rostellum generally well developed 
 and armed with a single crown of hooks, or it may be unarmed. Vas 
 deferens with internal and external seminal vesicles. Genital ducts dorsal 
 to the longitudinal excretory vessels, or exceptionally they may be between. 
 Pores unilateral. 
 
 Type species: Hymenolepis diminuta (Rudolphi 1819) Blanchard 1891. 
 
 List of the Species in the Genus Hymenolepis 
 
 All three testes lie close together or somewhat separated but not 
 so placed that the ovary lies between any two of them. Ovary 
 ventral, anterior, or posterior; but not lateral to the testes. 
 
 1. Hymenolepis breviannulata Fuhrmann 1906. 
 See Fuhrmann 1906c: 445 (Fig. 25). 
 
 2. Hymenolepis longicirrosa Fuhrmann 1906. 
 
 See Fuhrmann 1906e: 751-752 (Figs. 17 and 18). 
 
 3. Hymenolepis longivaginata Fuhrmann 1906. 
 See Fuhrmann 1906e: 752. 
 
 4. Hymenolepis pauciovata Fuhrmann 1906. 
 See Fuhrmann 1906c: 447 (Figs. 28-31). 
 
 5. Hymenolepis septaria von Linstow 1906. 
 See von Linstow 1906a: 177 (Fig. 21). 
 
 6. Hymenolepis serrata 1906. 
 
 See Fuhrmann 1906c: 448 (Figs. 32-33). 
 
 7. Hymenolepis solowiowi Skrjabin 1914. 
 See Skrjabin 1914: 467. 
 
 8. Hymenolepis himantopodis Krabbe 1869. 
 
 See Krabbe 1869: 309; Fuhrmann 1906e: 748. 
 
 9. Hymenolepis hemignathi Shipley 1897. 
 See Shipley 1897: 613-621, 10 fig. 
 
 10. Hymenolepis spinosa von Linstow 1906. 
 See von Linstow 1906a: 178 (Figs. 24-25). 
 
 11. Hymenolepis brasiliensis Fuhrmann 1906. 
 See Fuhrmann 1906c: 446 (Fig. 26). 
 
 12. Hymenolepis furcifera (Krabbe 1869). 
 
 See Krabbe 1869: 306 (Figs. 176-178); von Linstow 1908: 38-39 
 
 (Figs. 1-2). 
 
 See Krabbe 1869: 306 (Figs. 176-178) Linstow 1908: 38-39 (Figs. 1-2). 
 
39] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 39 
 
 13. Hymenolepis aequabilis (Rudolphi 1810) Cohn 1901. 
 
 See Krabbe 1869: 316-317 (Figs. 212-213 (Taenia aequabilis); Stiles 
 1896: 33-34 (Figs. 29-30) (Dicranotaenia aequabilis); Clerc 1903: 
 290-293 (Figs. 2, 16 & 24) (Drepanidotaenia aequabilis). 
 
 14. Hymenolepis musculosa Clerc 1903. 
 
 See Clerc 1903: 303-3-5 (Figs. 17, 23, 29). 
 
 15. Hymenolepis upsilon Rosseter 1911. 
 
 See Rosseter 1911: 147-160 (Figs. 1-9); Fuhrmann; 1913: 26 (Figs. 18- 
 20). 
 
 16. Hymenolepis villosa (Bloch 1782) Wolffhiigel 1899. 
 
 See Krabbe 1869: 303-304 (Figs. 168-169) (Taenia villosa); 1882: 
 354-355 (Fig. 19-22). Wolffhiigel 1900: 184-188, fig. 11. 
 
 17. Hymenolepis compressa (Linton 1892) Fuhrmann 1906. 
 
 See Linton 1892: 108-110 (Figs. 83-92) (Taenia compressa). Ko- 
 walewski 1907: 775 (Figs. 7-11) 1908: 638-641 (Figs. 7-11). 
 
 18. Hymenolepis baschkiriensis Clerc 1903. 
 See Clerc 1903: 288-290. 
 
 19. Hymenolepis exigua Yoshida 1910. 
 See Yoshida 1910: 235 (Figs. 1-10). 
 
 20. Hymenolepis fragilis (Krabbe 1869) Fuhrmann 1906. 
 
 See Krabbe 1869: 300-301 (Figs. 158-160) (Taenia fragilis). Fuhr- 
 mann 1906e: 747-748 (Figs. 11-12). 
 
 21. Hymenolepis macrocephala Fuhrmann 1913. 
 See Fuhrmann 1913: 19-21 (Figs. 9-11). 
 
 22. Hy?nenolepis nitida (Krabbe 1869) Clerc 1902. 
 
 See Krabbe 1869: 294 (Figs. 133-135) (Taenia nitida). Clerc 1903: 
 310-315 (Figs. 26, 27, 30, 31, 36, 38, 40-42). 
 
 23. Hymenolepis nitidulans (Krabbe 1882) Fuhrmann 1906. 
 
 See Krabbe 1882: 353 (Figs. 16, 17) (Taenia nitidulans); Rosseter 
 1907: 36-39 (Figs. 1-15). 
 
 24. Hymenolepis pachycepkala (von Linstow 1872) Fuhrmann 1906. 
 See von Linstow 1872: 55 (Fig. 2-4) (Taenia pachycepkala); 1904: 305. 
 (Fig. 17-20) (Drepanidotaenia pachycepkala). 
 
 25. Hymenolepis rectacantha Fuhrmann 1906. 
 See Fuhrmann 1906c: 446-447 (Fig. 27). 
 
 26. Hymenolepis trijolium von Linstow 1905. 
 See von Linstow 1905: 361-362 (Fig. 6-7). 
 
 27. Hymenolepis lobulata n. sp. 
 See this, p. 43. 
 
 28. Hymenolepis cuneata n. sp. 
 See this, p. 45. 
 
 The two antiporal testes separated from the poral and the space 
 thus formed occupied by the female reproductive glands. 
 
40 ILLINOIS BIOLOGICAL MONOGRAPHS [40 
 
 29. Eymenolepis anatina (Krabbe 1869) Cohn 1901. 
 
 See Krabbe 1869: 287-288 (Figs. 114-116) {Taenia anatina). Schmidt 
 1894: 65-112 (PL 6) {Taenia anatina). Stiles 1896: 39-40 (Figs. 100- 
 115) {Drepanidotaenia anatina). 
 
 30. Eymenolepis bisaccata Fuhrmann 1906. 
 SeeFuhrmann 1906c: 444-445 (Figs. 21-24). 
 
 31. Eymenolepis capillaris (Rudolphi 1810) Fuhrmann 1906. 
 
 See Krabbe 1869: 307, (Fig. 179) {Taenia capillaris). This species is 
 placed in this genus on the basis of the statement of the similarity 
 between E. capillaris and E. multistriata made by Fuhrmann, 1908: 
 75, but its relationships are incompletely understood. 
 
 32. Eymenolepis clandestina (Krabbe 1869) Cohn 1904. 
 
 See Krabbe 1869: 316 (Fig. 208-209) {Taenia clandestina). Cohn 
 1904: 243-246 (Figs. 9-12). 
 
 33. Eymenolepis creplini (Krabbe 1869). 
 
 See Krabbe 1689: 317 (Figs. 214-215) {Taenia creplini). Cohn 1901: 
 304-307 (Figs. 31-33). 
 
 34. Eymenolepis echinocotyle Fuhrmann 1907. 
 See Fuhrmann 1907: 532-533 (Figs. 37-38), 
 
 The Zoologisches Museum der Universitat, Berlin, very kindly gave 
 material of this species to the Ward Helminthological Collection at 
 the University of Illinois, Urbana; this was of great value in the 
 author's work. This courtesy was greatly appreciated. 
 
 35. Eymenolepis inermis Yoshida 1910. 
 
 See Yoshida 1910: 239-241 (Figs. 11-16). 
 
 36. Eymenolepis kowalewski Baczynska 1914. 
 See Baczynska 1914: 219-221 (Figs. 51-54). 
 
 37. Eymenolepis linea (Goeze 1782) Wolffhiigel 1899. 
 
 See Krabbe 1869: 327-328 (Figs. 248, 249) {Taenia linea) . Wolffhiigel 
 1900: 189-190 (Fig. 112). 
 
 38. Eymenolepis multistriata (Rudolphi 1805). 
 See Cohn 1901: 302-304 (Fig. 30). 
 
 39. Eymenolepis retracta von Linstow 1905. 
 See von Linstow 1905b: 4 (Fig. 15). 
 
 40. Eymenolepis meglahystera von Linstow 1905. 
 See von Linstow 1905b: 5 (Figs. 16-18). 
 
 41. Eymenolepis orthacantha Fuhrmann 1906. 
 See Fuhrmann 1906e: 754 (Figs. 23-25). 
 
 For this species also the author is indebted to the Zoologisches Museum 
 der Universitat, Berlin, which donated alcoholic material upon the 
 request of Professor Ward to the Helminthological Collection at the 
 University of Illinois, Urbana. 
 
 42. Eymenolepis sacciperhim n. sp. 
 See this report, p. 48. 
 
41] STUDIES ON AVIAN SPECIES OF BYMENOLEPIDIDAE—MAYHEW 41 
 
 The two testes on the side toward the pore separated from the 
 third, the space between occupied by the female reproductive 
 glands. 
 
 43. Hymenolepis multiglandularis Baczynska 1914. 
 See Baczynska 1914: 211-214 (Figs. 40-44). 
 
 44. Hymenolepis brachycephala (Creplin 1829). 
 
 See Krabbe 1869: 294-295 (Figs. 136-140) {Taenia brachycephala). 
 Cohn 1901: 280-284 (Figs. 13-14). 
 
 Ovary antiporal to the three testes but extending beneath the 
 antiporal testis. 
 
 45. Hymenolepis przewalskii Skrjabin 1914. 
 SeeSkrjabin 1914: 471. 
 
 46. Hymenolepis venusta Rosseter 1896. 
 SeeRosseter 1898: 10-23 (Figs. 1-17). 
 
 47. Hymenolepis ardeae (Rudolphi 1819). 
 
 See Fuhrmann 1906c: 451-452 (Figs. 37-39) (H. ardeae); 1906e: 740. 
 Grateful acknowledgement is here made to the Zoologisches Museum 
 der Universitat, Berlin, for loan of material of this species for study. 
 
 48. Hymenolepis elongate Fuhrmann 1906. 
 See Fuhrmann 1906e: 450 (Fig. 36). 
 
 49. Hymenolepis setigera (Frolich 1789) Cohn 1901. 
 
 See Stiles 1896: 41-42 (Figs. 147-150) (Drepanidotaenia setigera); 
 Clerc 1903: 298-302 (Figs. 3, 6, 7, 12, 22) (Drepanidotaenia setigera); 
 Fuhrmann 1906e: 734. 
 
 50. Hymenolepis bilateralis von Linstow 1905. 
 See von Linstow 1905b: 5-6 (Figs. 19-21). 
 
 Ovary entirely antiporal to the three testes. 
 
 51. Hymenolepis lanceolata (Bloch 1782) Weinland 1858. 
 
 See Stiles 1896: 36-37 (Figs. 43-53, 54-55) (Drepanidotaenia lance- 
 olata); Clerc 1903: 302-303, figure 4 (D. lanceolata). Ransom 1904: 
 14, 101-110 (Figs. 108-130). 
 
 52. Hymenolepis tenuirostris (Rudolphi 1819) Cohn 1901. 
 
 See Stiles 1896: 43 (Figs. 165-172) (Drepanidotaenia tenuirostris); 
 Cohn 1901: 326-327. 
 
 Ovary on the poral side of the proglottid; all three testes antiporal 
 to the ovary. 
 
 53. Hymenolepis biaculeata Fuhrmann 1910. 
 
 See Fuhrmann 1910: 21-22 (Figs. 17-21); 1909: 41. 
 
 The two lateral testes placed lateral to the longitudinal excretory 
 vessels on each side. 
 
42 ILLINOIS BIOLOGICAL MONOGRAPHS [42 
 
 54. Hymenolepis microcephala (Rudolphi 1819). 
 Synonyms H. leptoptile Linstow 1901. 
 
 H. multiformis Creplin 1828. 
 
 This is a very interesting species and deserves some discussion at this 
 point. It has been recorded from Ciconia ciconia, Pyrrherodias purpurea, 
 Abdimia abdimia, Plegadis falcinellus, Ardea cinerea, Nycticorax nycticorax, 
 all of which are Ciconiiformes and from Europe and Africa. The species 
 is described as having a length of from 100 to 300 mm. That this is a very 
 characteristic form is indicated by the position of the testes. They are so 
 placed that the two lateral ones are outside the excretory vessels, and, 
 according to Cohn (1909: Taf. XI, fig. 14) in a transverse row, while 
 Fuhrmann (1909) figures (Fig. 41, p. 43) and described them quite differ- 
 ently. Concerning the position of the genital pore, Cohn says: "Der 
 Genitalporus liegt in der Mitte des Gliedrandes auf der rechten Seite auf 
 einer konischen kleinen Erhohung des Gliedrandes." Fuhrmann (1909) 
 described the testes as follows: 'Die Hoden zeigen eine sehr typische 
 Disposition in dem sie was bei keiner anderen Hymenolepisart der Fall (mit 
 Ansnahme von H. multiformis (Crepl.) so angeordnet sind, dass die beiden 
 seitlichen Hoden ausserhalb der beiden weit nach innen verschobenen 
 dorsalen ventralen Wassergefasspaare liegen. Der mediane Hoden liegt 
 vor den weiblichen Genitalien." 
 
 The differences between the forms described by Cohn and Fuhrmann 
 indicate that a re-examination of the specimens should be made, but the 
 position of the testes with reference to the excretory vessels is so character- 
 istic and stands in such marked contrast to the other species of the 
 Hymenolepis group that a more careful study may result in the placing 
 of this species in a separate genus. However, it is not possible to define 
 exactly the characters of such a genus at present. 
 
 Position of testes with reference to the ovary uncertain 
 
 55. Hymenolepis kempi (Southwell) 1921. 
 Synonym Dilepis kempi Southwell 1921. 
 Host: Phalacrocorax pygtnaeus. 
 
 Locality: North Lohtak Lake, Manipur, Assam. 
 
 Length 5 cm. Greatest width 1 mm. Posterior proglottids 900ju broad 
 by 400// long. Genital pores unilateral. Scolex 220/x long by 400m broad. 
 Rostellum about 170jU. long by about 160/x broad. Hooks 20 in two rows, 
 those in the posterior row 135ju and those in the anterior about 175/x in 
 length. Testes in the median field and, according to figure 2, in a transverse 
 row. Genital ducts pass dorsal to the excretory ducts. Uterus large and 
 sac-like, with numerous out-pocketings, and reaching the excretory vessels 
 on either side. 
 
43] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 43 
 
 The small and almost constant number of the testes is such an out- 
 standing characteristic of the genera and species of the family Hymeno- 
 lepididae that it separates them from other Cestoda in a natural and 
 distinct manner. After a study of this large number of species and of the 
 data presented in this report, I do not believe this species ought to be 
 excluded from the family on the basis of the double crown of hooks. 
 
 DESCRIPTION OF NEW SPECIES 
 
 HYMENOLEPIS LOBULATA N. SP. 
 [Figs. 32-39] 
 
 The specimens upon which the following description is based were 
 collected by N. C. Gilbert at Bass Lake, Michigan, June 9, 1907, and are 
 preserved in the collection of Professor H. B. Ward (No. 17, 180). In this 
 study cotypes were selected comprising sixteen toto mounts and seven 
 sets of serial sections, catalogue numbers 25.5 to 25.13 inclusive. They 
 remain in the Ward Helminthological Collection at the University of 
 Illinois, Urbana. The host was a single specimen of Podilymbus podiceps 
 (Linnaeus) or the pied-billed grebe, and the organ the intestine. 
 
 External anatomy: The specimens vary from about 60 mm to 85 mm 
 in length and from 2 to 2.5 mm in width. The width immediately behind the 
 scolex varies from less than 100 to 225/1 depending upon the state of con- 
 traction of the strobila. The width at a number of points was measured in 
 one specimen and is as follows: 20 mm from the scolex, 0.6 mm; 30 mm, 
 1.3 mm; 26 mm, 1.7 mm; 38 mm, 2mm; 68 mm, 2 mm; 86 mm, 1.5 mm. 
 The proglottids are all much wider than long. 
 
 The scolex is 0.6 mm in diameter and almost spherical. The four 
 rounded suckers are 0.25 mm in diameter and but slightly raised above the 
 surface. The rostellum (Fig. 37) has a very interesting shape. It is long 
 and slender, and generally twisted and coiled in preserved specimens. It is 
 crowned at the tip by a knob-like enlargement which has deep marginal 
 lobes, each of which carries a hook on its lateral margin. Anteriorly, this 
 enlargement is but slightly arched. This enlargement is 0.1 mm in diam- 
 eter, while the stalk part is but 35^i in diameter by about 0.2 mm long. 
 When the rostellum is retracted, the points of the hooks are directed 
 anteriorly, while in the extended condition they are directed backward, 
 showing that the rostellum is an introvert. In the partially retracted 
 condition, they are placed regularly in two rows in a manner indicated in 
 figure 34, while in the completely retracted condition they are closely 
 packed together. The hooks are eight to eleven in number, 14 to 17/u in 
 length, and are shaped like figure 35. Of the scoleces examined, one had 
 eight hooks, three had nine hooks, three had ten, one had eleven, and one 
 had lost all but one hook. 
 
44 ILLINOIS BIOLOGICAL MONOGRAPHS [44 
 
 The three testes are placed in a transverse row, two of them being on 
 the poral side of the proglottid. The well-differentiated beginnings of 
 the ovary and vitellaria are distinguishable in the space between and 
 just posterior to the two poral and the antiporal testes in proglottids 
 about 35 mm from the scolex. In this region the testes are oval in outline 
 and 0.2 to 0.25 by 0.15 mm in size. The cirrus sac reaches to or slightly 
 beyond the inner large ventral excretory vessel, and is surrounded by a 
 layer, several cells in thickness, of large clear angular cells. The internal 
 seminal vesicle occupies the larger part of the interior, while the cirrus is 
 a very narrow straight tube which opens into the small, slender and deep 
 genital atrium just dorsal to the vagina. The external seminal vesicle is 
 an elongate, thin-walled structure which is to be found anterior to and 
 between the two poral testes. The testes have functioned and are found 
 to be disappearing in proglottids about 50 mm from the scolex. The pore 
 is to be found on the right hand border in the anterior one-third of the 
 lateral margin. 
 
 The start of the ovary is to be found in proglottids about 35 mm from 
 the scolex in the form of a transversely elongated structure with a few 
 small lobes on the anterior border. As development proceeds, it elongates 
 transversely and the lobes increase in number and depth so that in pro- 
 glottids about 50 mm from the scolex, the organ has the outline and 
 extent as indicated in figure 38. The vitelline gland is situated posterior 
 to the ovary and is a transversely elongated oval organ but slightly lobed. 
 The vagina is at first a clearly differentiated, thin-walled duct which leads 
 at first almost directly medially, then posteriorly ventral to the poral 
 testes, then posterior to the median testes to the region of the beginnings 
 of the ovary and vitellaria. Its inner end is slightly wider than the re- 
 mainder of its length and becomes widely expanded into a seminal recep- 
 tacle. Its entire length serves, however, as a reservoir for the spermatozoa, 
 since it becomes a wide tube and completely filled with them. Its course 
 when filled with the spermatozoa in the mature proglottids is very ir- 
 regular and contains several curves. Both the cirrus sac and vagina pass 
 dorsal to the longitudinal excretory vessels. The uterus is a large transverse 
 sac divided irregularly into lobes. The eggs in all the specimens examined 
 were immature. They have but two shells and no hooks could be made 
 out in any that were examined. The space between the shells is filled 
 with a loose cellular mass which appeared to be breaking up in more 
 mature eggs. The embryos are spherical and vary in diameter from 7 to 
 12/j. and the shell 18 to 28/jl. These measurements, however, are not 
 thought to be of much value, especially those of the shell, since they are 
 very much distorted by pressure from adjoining eggs and by shrinkage. 
 The longitudinal muscles are irregularly placed and all the bundles 
 are of about the same size. Their position varies according to the position 
 
45] STUDIES ON AVIAN SPECIES OF BYMENOLEPIDIDAE—MAYHEW 45 
 
 in the proglottid at which the section is selected, being farther from the 
 surface in the posterior than in the anterior. The longitudinal nerve lies 
 about midway between the large excretory vessel and the border of the 
 proglottid. The dorsal excretory vessel is 26 by 10^i in proglottids about 
 35 mm from the scolex, while the ventral is much larger, being 21 by 8/x 
 size in the same region. No connections could be found between the 
 ducts of the two sides. 
 
 Of the species described from the order Pygopodes as listed by Fuhr- 
 mann (1908), E. capillaris deserves some discussion. The shape of the 
 rostellum is apparently flat as figured by Krabbe (1869) and not lobed. 
 The hooks as figured by Krabbe are different in shape, the basal part 
 being much more curved and the blade more bent, although the size as 
 given by Krabbe is 15/x. The position of the testes and ovary is not well 
 understood. The hooks of H. furcifera (Krabbe 1869) are 26 to 33/x in 
 length and much different in shape, the blade being much longer, heavier, 
 and the base more curved than found in the species described above. 
 Wardiam capillaroidcs Fuhrmann (1906: 355) from Podiceps dominions 
 (L.) has two of the testes on the antiporal side, the farther one somewhat 
 variable in position but usually in a transverse row. The hooks of this 
 species are larger (21ju) and much more slender in structure in all parts 
 than in the above described species. H. podicipina Szymanski 1905 has 
 much smaller testes which are arranged two antiporal, one of which is 
 in front of and ventral to the other. The hooks have much heavier basal 
 parts and about three times as long (42 to 46,u) as in the new species 
 described above. 
 
 Of the species which have the testes sufficiently well described to deter- 
 mine their location, H. breviannidata (Fuhrmann 1906c) deserves mention. 
 The testes, however, are much smaller, being 0.04 mm in diameter while in 
 the species described above they are about 0.25 mm long and 0.15 mm 
 wide. The ovary is median and although not stated is presumably ventral 
 to the median testes while in our species it is mainly between the two testes 
 on the side away from the pore. The scolex was absent from Fuhrmann's 
 species. The other species which are related to the above described form 
 by having the testes in a transverse row, are all markedly different in the 
 shape and size of the hooks, ovary, and cirrus. 
 
 HYMENOLEPIS CUNEATA N. SP. 
 [Figs. 48-53] 
 
 The specimens forming the basis of the description of this species were 
 obtained from a wild duck killed at Table Rock, Nebraska, on June 22, 
 1896, and are preserved in the collection of H. B. Ward. 
 
 Of these specimens the following mounts, consisting of eight totos and 
 five sets of serial sections, numbers 25.14 to 25.20 inclusive, were desig- 
 
46 ILLINOIS BIOLOGICAL MONOGRAPHS [46 
 
 nated as cotypes. They remain in the Ward Helminthological Collection 
 at the University of Illinois, Urbana. 
 
 External Anatomy. The specimens of this species vary from 30 to 40 
 mm in length, those of about 30 mm usually lacking eggs in the uterus but 
 have the female organs well developed. The shape of the strobila is 
 peculiar in that the widest part is usually from 3 to 5 mm from the posterior 
 end, and tapers gradually toward the scolex, the general form thus being 
 wedge-shaped. Specimens vary from 3 to 4 mm wide at the widest point 
 and from 0.5 to 1 mm wide at the central part of the strobila. The posterior 
 portion is evenly rounded behind the widest part, and the last proglottid is 
 sterile and much smaller than those immediately in front. Strobilae 30 to 
 35 mm long have from 200 to 250 proglottids while those about 40 mm long 
 have about 300. The genital pores are unilateral and on the right side 
 of the proglottid. No irregularity in the structure of the genital organs 
 or the general structure of the proglottids has been observed. 
 
 The scolex is a strongly developed structure, measuring about 0.35 
 mm in diameter, and carrying four suckers, each of which are about 0.15 
 mm in diameter. The rostellum is provided with a sac which occupies 
 about one-third the diameter of the scolex. The rostellum is a solid mus- 
 cular organ of about the same diameter throughout its entire length, and 
 is not retracted into the rostellar sac as an introvert. It carries from six 
 to eight very sharp and strong hooks arranged in a single row about its distal 
 end. Two specimens were found to possess six hooks, one had seven , and three 
 had eight, so it is evident that the number is by no means constant. The 
 hooks are large enough and placed far enough apart so that there is little 
 difficulty in making an accurate count. They vary in length from 103 to 
 115^, the majority measuring from 105 to 108ju; only four were found 
 which measured 112 and 115^. 
 
 The three testes he in a transverse row in the center of the proglottid and 
 are about equally spaced. They are somewhat oval and measure about 
 500/x along the transverse diameter of the proglottid, 170/x dorsoventrally, 
 and about 100/x antero-posteriorly in proglottids about 22 mm from the 
 scolex. The larger part of the ovary is found anterior to and on the an- 
 tiporal side of the middle testes. It occupies the larger part of the central 
 region of the proglottid when fully developed. The vasa efferentia arise 
 on the median side of the two lateral testes and on the dorsal side of the 
 median testes. The ducts from the two poral testes join, and the short 
 common duct thus formed unites with the vasa efferentia from the an- 
 tiporal testes. The vas deferens soon communicates with the external, 
 seminal vesicle at its median end. The latter communicates with the 
 internal seminal vesicle through the slightly coiled remaining portion of 
 the vas deferens, which lies dorsal and anterior to the poral testis. The 
 external seminal vesicle lies dorsal and anterior to the region between the 
 two poral testes. 
 
47] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 47 
 
 The cirrus sac lies dorsal to the excretory ducts as does the vagina. 
 A rather large and somewhat dumb-bell shaped internal seminal vesicle 
 occupies about three-fourths of its inner portion and communicates with 
 the cirrus by means of a wide duct. The vas deferens communicates with 
 the internal seminal vesicle at its inner end, which lies against the wall of 
 the sac, and the duct leading to the cirrus arises at the end of the vesicle 
 nearest the pore. The latter passes back alongside the vesicle to the inner 
 enlarged end where it enters the cirrus. The cirrus extends inward about 
 three-fourths the length of the sac and lies along one side of the wall for 
 the greater part of its length. It is usually straight but in some instances 
 is slightly bent or coiled in parts, and is provided with hooks only along 
 its outer portion. The vagina opens ventrally and somewhat posteriorly 
 to the cirrus into the genital atrium. The latter varies much in depth 
 in different parts of the strobila. The total length of the internal seminal 
 vesicle is about 500jU, the width of the inner enlargement 60 to 75/x, and of 
 the outer 50 to 60/j. in proglottids about 22 mm from the scolex. The cirrus 
 sac is about 1 mm in length in this region. 
 
 The beginnings of the ovary and other female reproductive organs 
 appear in proglottids about 20 mm from the scolex, and are fully developed 
 about 30 mm from the scolex. The ovary is deeply divided into 15 to 20 
 irregular rounded lobes, and lies anterior and ventral to the median testes 
 occupying the middle one-third of the proglottid. The vitelline gland is 
 likewise lobed and lies in the concavity in the posterior side of the ovary. 
 The ootype is rounded and is located ventral to the vitelline gland. 
 
 The vagina opens on a well marked papilla which is ventral and 
 anterior to the opening of the cirrus sac. The two do not usually open on 
 the same level, but the vagina into a deep depression of the genital atrium 
 extending back along the cirrus sac. The lateral portion of the vagina is a 
 narrow duct which lies close to the cirrus sac and the vas deferens until 
 it widens out to form the thin-walled seminal receptacle. The latter is 
 found just beyond the seminal vesicle and about on the same level in 
 young proglottids. The duct leading from it to the region of the female 
 reproductive organs can be traced. As development proceeds, almost 
 the entire median portion of the vagina becomes distended by spermatozoa, 
 forming a very large seminal vesicle extending almost to the excretory 
 vessels, and occupying the larger portion of the central region between 
 the muscular layers in proglottids about 30 mm from the scolex. The 
 seminal receptacle is first evidenced by a slight widening of the duct just 
 beyond the seminal vesicle, and as development proceeds, this widening 
 is found to extend along the duct toward the pore, and in mature proglottids 
 this whole portion of the duct becomes filled with spermatozoa as described 
 above. 
 
 The uterus is a sac-like structure, which extends, on either side beyond 
 the excretory vessels, and fills the larger part of the ripe proglottids. It is 
 
48 ILLINOIS BIOLOGICAL MONOGRAPHS [48 
 
 deeply divided into irregular lobes by septa. The eggs, in every specimen 
 examined, were found to be very immature, being only rounded or oval 
 masses of cells and showing no shell. 
 
 The longitudinal muscles are very well developed and are in two 
 irregular layers on either side of the proglottid. The outer one has the 
 bundles usually of a smaller size than those of the inner, though some are 
 as large as those of the inner layer. No oblique muscle bundles could be 
 located. Two groups of from four to six longitudinal muscle bundles are 
 found on each side of the proglottid, one on either side of the spaces between 
 the testes. Two longitudinal excretory vessels lie on either side of the 
 proglottid, ventral to the vagina and cirrus sac. The larger one is ventral 
 and measures about 50/jl in diameter about 20/x mm from the scolex. The 
 smaller one is about 20ju in diameter in the same region, and lies invariably 
 directly dorsal to the larger. A careful examination of these in sections 
 failed to reveal any transverse ducts joining those on opposite sides of the 
 proglottid. 
 
 A comparison of this species with others is indeed difficult, because 
 there has been no description found which shows a similar combination of 
 characters. When compared with the other species which have the testes 
 arranged in a transverse row, none are found which show any resemblance 
 to it. Likewise when the hooks are compared, there are no others which 
 have such large ones of a similar shape and number except H. macracanthos, 
 v. Linstow 1877, but these are different in that there is no projection on 
 the posterior basal portion. This species was described from an immature 
 specimen and consequently could belong to any one of several genera as 
 pointed out elsewhere in this report. 
 
 When the descriptions of the species that have been found in Anseri- 
 formes are compared, no one is found which compares with it in size and 
 shape of hooks and arrangement of the internal organs. It seems proper 
 to conclude therefore that this form is an undescribed species. 
 
 HYMENOLEPIS SACCIPERIUM N. SP. 
 [Figs. 40-47] 
 
 The material which formed the basis for the following description was 
 taken from the intestine of two specimens of Marila marila, American 
 scaup duck, or bluebill, one of which was killed at Peoria, Illinois, Novem- 
 ber 25, 1923, and the other at Lincoln, Nebraska, April 11, 1908. The 
 specimens from the host taken at Peoria, Illinois, are in the collection of 
 the author under the number 584a, and are designated as cotypes. In the 
 Ward Helminthological Collection at the University of Illinois, Urbana, 
 there are eight mounts, five totos and three sets of serial sections, numbers 
 25.21 to 25.26 inclusive. These were prepared from the specimens taken at 
 
49] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYBEW 49 
 
 Lincoln. The type is No. 25.21 in the Ward Collection of Parasites at 
 Urbana. 
 
 External Anatomy. The length of specimens which have well developed 
 eggs in the posterior proglottids is about 38 cm. The width increases 
 gradually from 150/i immediately behind the scolex to the greatest width, 
 1.25 mm to 2 mm, 9 to 10 cm from the scolex. Throughout the greater 
 part of the remainder of the strobila, the width is about the same, but de- 
 creases slightly toward the posterior end. The above measurements are 
 for specimen No. 584a3. The proglottids are about 35/x long at about 35 
 mm from the scolex. They increase to 160/x 60 mm from the scolex, while 
 posterior proglottids with well filled uteri measure 1.7 mm wide by 0.32 mm 
 long in larger specimens. The suckers are 60jU wide, inconspicuous, and 
 but slightly raised above the surface of the scolex. 
 
 The scolex is rounded and not conspicuously set off from the neck region 
 behind. It is 0.2 mm wide, while the width of the neck region is about 
 0.15 mm at its center. The rostellum is short in proportion to the width of 
 the scolex, being about 25/i in length and 60/j wide. The tip of the rostellum 
 is dome-shaped and bears a single row of hooks about its margin. The hooks 
 are from 18 to 22 in number and are from 14 to 17/x. long and have the 
 shape indicated by figure 43. The neck region is short, strobilization being 
 evident 1.3 mm behind the scolex by slight constrictions in the surface 
 of the strobila. 
 
 The testes are the most conspicuous structures in the entire proglottid. 
 They lie in a transverse row, occupy almost the entire space between the 
 muscular layers, and extend antero-posteriorly almost the full length of 
 the proglottid. The number varies from one to four, about 93 to 95 per cent 
 of the proglottids having three, while in the remainder there are one, two, 
 and four, one being much rarer than any of the other numbers. The 
 arrangement of these with reference to the ovary, vitelline gland and shell 
 gland is likewise very variable; in those proglottids with four testes, three 
 of this number are either on the antiporal side and one on the poral, or two 
 may be on each side, but never three on the poral side; of those having 
 three, two may be on the poral or antiporal side or all three may be on the 
 antiporal side, but never all on the poral; in cases where there are two 
 testes, both may be on the antiporal side, or one may be on either side of 
 the ovary, the latter being slightly more frequent than the former. Pro- 
 glottids which have one, have this testis on the poral side in the few 
 instances observed. The testes vary much in size and shape in different 
 proglottids, but they are about 0.2 mm in diameter in proglottids while 
 the ovary is about that size. The testes are frequently lobed or deeply 
 constricted usually in the longitudinal axis of the strobila. 
 
 The vasa efferentia arise on the anterior, poral side of the antiporal 
 testes and on the anterior antiporal sid'e of the poral testes in those pro- 
 glottids having three testes. The duct from the farthest antiporal testes 
 
SO ILLINOIS BIOLOGICAL MONOGRAPHS [SO 
 
 passes anterior and slightly ventral to the median testes and uniting with 
 the one from the latter forming a duct which joins the vas deferens from 
 the poral testes about midway between the poral and the median testes. 
 Considerable irregularity has been observed in these ducts, as is indicated 
 in figure 5, but this seems to be confined to the region where they pass into 
 the vas deferens. These irregularities in the testes occur in the material 
 from both hosts. The vas deferens thus formed then passes to the external 
 seminal vesicle in an almost straight line. 
 
 The cirrus sac is about 0.3 mm long and extends medially and anteriorly 
 from the pore which lies about the center of the margin of the proglottid 
 on the right hand side. The internal seminal vesicle occupies about the 
 inner half of the sac, while the cirrus with its attached muscles and asso- 
 ciated cells occupies the outer half. The cirrus is a straight tube in most 
 instances but is sometimes slightly coiled. So far as could be observed, it 
 is without hooks. The external seminal vesicle lies anterior to the poral 
 testis and is an elongate structure with thin walls. It is joined to the internal 
 seminal vesicle by a slightly coiled duct. The longitudinal excretory ducts 
 he beneath the inner end of the cirrus sac and the outer end of the vesicle. 
 
 The ovary is a crescent-shaped organ lying usually in the center of the 
 proglottid, but may be somewhat to the right or poral side, when there 
 are three testes on the antiporal side. It is but slightly lobed or indented, 
 and has the somewhat lobed vitelline gland lying in the hollow of the 
 crescent behind. The ootype, and female genital ducts lie between the 
 vitillaria and ovary and somewhat ventral to both. The seminal receptacle 
 is the wide, thin-walled, somewhat coiled portion of the vagina which 
 lies anterior and medial to the poral testes. It is widely distended with 
 spermatozoa in proglottids which have the female organs well developed. 
 The vagina is a wide duct leading from its outer end to its point of opening 
 into the genital atrium ventral to the opening of the cirrus. It lies ventral 
 to and along the posterior side of the external seminal vesicle and ventral 
 to the cirrus sac; in the region of the latter it is usually somewhat bent. 
 
 The uterus passes dorsal to the excretory vessels on either side, bends 
 ventrally, passing ventral to the testes, and dorsally again above the ovary, 
 vitelline and shell glands. In the ripe proglottids the uterus occupies 
 almost the entire proglottid. It is slightly lobed or indented on both 
 margins and has the remnant of the seminal receptacle lying in a cavity 
 in its anterior right-hand margin. The number of eggs which the uterus 
 contains varies considerably in different proglottids, some having only a 
 few while others are packed. The eggs were mature in specimens from both 
 hosts, and were essentially the same size. The shells are relatively thick 
 and each of the outer ones were observed to have nuclei within as indicated 
 in figure 42. The middle shell averages 33 by 28^i in size with a maximum 
 length and width of 37 by 32/x, and a minimum of 28 by 12ju. The outer 
 shell was so distorted by shrinkage that scarcely any eggs could be found 
 
51] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 51 
 
 which had it well enough preserved for measurement. Its size on the one 
 from which the drawing was made was 40^ in diameter. The embryos 
 possess six slender hooks, and average 28 by 15/j. in size. Their maximum 
 length and width is 32 by 18/x and their minimum 16 by 13/x. 
 
 There are two pairs of longitudinal excretory vessels running through 
 the lateral portion of the strobila. The ventral vessel on each side is much 
 the larger of the two, being about 53 by 25ju in size about 55 mm from the 
 scolex, being elongated in the transverse diameter of the proglottid, while 
 the dorsal is but about 15yu in diameter in the same region. An examination 
 of the walls reveals no indication of transverse vessels connecting the 
 longitudinal vessels in any part of the proglottid. The longitudinal muscles 
 are but weakly developed, there being approximately 100 bundles on 
 both the dorsal and ventral sides of the proglottid. The oblique muscles 
 are conspicuous and well developed. They lie outside the longitudinal and 
 near the surface of the proglottid. 
 
 An examination of the descriptions of the species that are sufficiently 
 complete to state the position of the testes reveals none which are com- 
 parable in general characters to the one described above. There is no 
 description in which any detailed reference is made concerning the varia- 
 tions in the number of testes. This characteristic is so noticeable in this 
 species that it seems that it would not have escaped the attention of any 
 one who had examined it. 
 
 When the literature descriptive of the species found in Anseriformes is 
 examined, the first species to attract one's attention is W einlandia coronula 
 (Dujardin) 1845, which has 20 to 26 hooks 14 to 19^ long. The hooks are 
 shaped much like those of the species described above, but are somewhat 
 more strongly constructed throughout in all parts. The musculature of the 
 two species is somewhat similar (Wolffhiigel 1900) in that the inner 
 longitudinal layer of bundles consists of a relatively few large conspicuous 
 bundles on the dorsal and ventral sides, (six in W. coronula and 10 to 12 in 
 our species on either side) and two or three bundles above and below the 
 excretory vessels near the margin of the worm. The cirrus sac, cirrus, 
 external and internal seminal vesicles, and location of the female repro- 
 ductive organs are very similar. The outstanding difference, however, is 
 found in the position of the testes. Fuhrmann (1906: 733) says that the 
 two antiporal testes are arranged so that one is anterior and median in 
 position with reference to the other, and Meggitt (1920: 307) says that in 
 the extended specimens studied by him, they have this position though in 
 strongly contracted ones the three may he in a straight line, yet there is 
 always a small projection of the outer testes lying behind the inner so 
 that there is always a distinction into anterior and posterior testes. The other 
 species found in the Anseriformes having the hooks similar in number and 
 length have no resemblance to the above described form in internal struc- 
 ture. It seems justifiable, therefore, to designate this form as a new species. 
 
52 ILLINOIS BIOLOGICAL MONOGRAPHS [52 
 
 GENUS WEINLANDIA NOV. GEN. 
 
 Three testes in a proglottid, two located on the posterior border and 
 the third directly anterior, anterior and median, or anterior and lateral to 
 the antiporal posterior testis. Rostellum generally well developed and 
 armed or unarmed. Vas deferens with an internal and an external seminal 
 vesicle. Genital ducts dorsal to the longitudinal excretory vessels or 
 exceptionally between or below. Pores unilateral. 
 
 Type species: Weinlandia macrostrobilodes n. sp. 
 
 LIST OF THE SPECIES OF WEINLANDIA 
 
 Two testes posterior, the third anterior and lateral to the posterior 
 antiporal testis. 
 
 1. Weinlandia arcuata Kowaleski 1905. 
 
 SeeKowaleski 1905: 222-238; 1905a: 532-533 (Figs. 1-9). 
 
 2. Weinlandia cyrtoides n. sp. 
 See this paper, p. 59. 
 
 3. Weinlandia abortiva von Linstow 1904. 
 
 See von Linstow 1904a: 383 {Hymenolepis voluta): 1905: 362. 
 
 4. Weinlandia chionis Fuhrmann 1921. 
 
 See Fuhrmann 1921: 517-518 (Figs. 110-113). 
 
 5. Weinlandia collaris (Batsch 1786) Fuhrmann 1908. 
 
 See Stiles 1896: 40-41 (Figs. 116-146) {Drepanidotaenia sinuosa). 
 Cohn 1901: 323-325 {Eymenolepis sinuosa) . 
 
 6. Weinlandia diorchis Fuhrmann 1913. 
 See Fuhrmann 1913: 29-31 (Figs. 21-25). 
 
 7. Weinlandia farciminosa (Goeze 1782). 
 
 See Krabbe 1869: 321-322 (Figs. 230-232) {Taenia farciminalis). 
 Volz 1900: 32-35 (Fig. 10) {Diplacanthus farciminalis). 
 
 8. Weinlandia flagellata Fuhrmann 1906. 
 See Fuhrmann 1906b: 356-357 (Figs. 8-9). 
 
 9. Weinlandia globocephala Fuhrmann 1918. 
 See Fuhrmann 1918: 443-445 (Figs. 64-66). 
 
 10. Weinlandia gracilis (Zeder 1803) Cohn 1901. 
 
 See Stiles 1896: 38-39 (Figs. 80-99) {Drepanidotaenia gracilis) ; Wolff- 
 hiigel 1900: 176-183 (Figs. 106-109) {D. gracilis); Cohn 1901: 327- 
 329; Clerc 1903: 305-306 {D. gracilis). 
 
 11. Weinlandia glandularis Fuhrmann 1909. 
 See Fuhrmann 1909: 43-44 (Fig. 42). 
 
S3] STUDIES ON AVIAN SPECIES OF EYMENOLEPIDIDAE—MAYHEW 53 
 
 12. W einlandia j aegerskioeldi Fuhrmann 1913. 
 See Fuhrmann 1913: 25-26 (Figs. 15-17). 
 
 13. W einlandia longirostris (Rudolphi 1809). 
 
 See Krabbe 1869: 293; Fuhrmann 1906: 733. 
 
 14. W einlandia microsoma (Creplin 1829) Cohn 1901. 
 
 See Krabbe 1869: 296-298 (Figs. 146-150) (Taenia microsoma); 
 Cohn 1901: 284-288 (Figs. 15-22); Fuhrmann 1913: 23 (Figs. 12-14). 
 
 15. ~W einlandia meleagris (Clerc 1902) Fuhrmann 1906. 
 See Clerc 1902a: 574-575; 1903: 306. 
 
 16. W einlandia megalops (Nitzsch in Creplin 1829) Parona 1899. 
 See Ransom 1902: 158-167 (Figs. 11-14). 
 
 17. W einlandia lateralis n. sp. 
 See this paper, p. 56. 
 
 18. W einlandia papillata Fuhrmann 1906. 
 
 See Fuhrmann 1906b: 357-358 (Figs. 10-11). 
 
 19. W einlandia parvula Kowaleski 1905. 
 
 See Kowaleski 1905a: 533-534 (Figs. 10-17). 
 
 20. W einlandia rara Skrjabin 1914. 
 SeeSkrjabin 1914: 468. 
 
 21. Weinlandia stylosa (Rudolphi 1810) Volz 1899. 
 
 See Krabbe 1869: 326 (Figs. 242-244) (Taenia stylosa). Volz 1900: 
 141-144 (Fig. 9) (Diplacanthus stylosus). 
 
 22. Weinlandia styloides Fuhrmann 1906. 
 See Fuhrmann 1906: 354 (Figs. 3-5). 
 
 23. Weinlandia sphenocephala (Rudolphi 1809). 
 See Fuhrmann 1906: 449 (Figs. 34-35). 
 
 24. Weinlandia serpentula (Schrank 1788) Weinland 1858. 
 
 See Volz 1900: 135-140 (Fig. 8) (Diplacanthus serpentulus); Cohn 
 1901: 294-297 (Figs. 23-25); Clerc 1903: 295-296 (Fig. 8) (Drepani- 
 dotaenia serpentulus). 
 
 25. W einlandia tritesticulala Fuhrmann 1906. 
 See Fuhrmann 1907a: 531-532 (Figs. 34-36). 
 
 26. Weinlandia teresoides Fuhrmann 1906. 
 See Fuhrmann 1906c: 443-444 (Fig. 20). 
 
 27. Weinlandia vaginata Baczynska 1914. 
 
 See Baczynska 1914: 214-218 (Figs. 49-50). 
 
 Two testes posterior, the third anterior to the antiporal posterior 
 testis. 
 
 28. Weinlandia annandalei Southwell 1922. 
 See Southwell 1922: 374-377 (Figs. 10-13). 
 
 29. Weinlandia amphitricha (Rudolphi 1819) Fuhrmann 1906. 
 
 See Krabbe 1869: 311-312 (Figs. 195-197) (Taenia amphitricha); Clerc 
 1903: 293-295 (Fig. 21) (Drepanidotaenia amphitricha). 
 
54 ILLINOIS BIOLOGICAL MONOGRAPHS [54 
 
 30. Weinlandia brevis Fuhrmann 1906. 
 
 See Fuhrmann 1906e: 753-754 (Fig. 22). 
 
 31. Weinlandia columbina Fuhrmann 1909. 
 See Fuhrmann 1909: 41-42 (Fig. 38-40). 
 
 32. Weinlandia caroli Parona 1887. 
 
 See Fuhrmann 1906e: 741-743 (Fig. 3-7). 
 
 33. Weinlandia carioca (Magalhaes 1898) Ransom 1902. 
 
 See Ransom 1902: 151-158 (Fig. 1-10); 1905: 274-276 (Figs. 3, 10,22, 
 28); Guberlet 1919: 35-38. 
 
 34. Weinlandia corvi n. sp. 
 See this paper, p. 62. 
 
 35. Weinlandia interrupta (Rudolphi 1802) Fuhrmann 1906. 
 See Fuhrmann 1906e: 745-746. 
 
 36. Weinlandia intermedia Clerc 1906. 
 See Clerc 1906: 436 (Figs. 7-9). 
 
 37. Weinlandia inflata (Rudolphi 1809). 
 See Cohn 1901: 330-331. 
 
 38. Weinlandia importata Fuhrmann 1918. 
 See Fuhrmann 1918: 447-449 (Fig. 75-78). 
 
 39. Weinlandia ibidis Johnston 1911. 
 See Johnston 1911: 88 (Figs. 22-24). 
 
 40. Weinlandia ligidoides (Gervais 1847). 
 
 See Fuhrmann 1906e: 741-745; Cohn 1901: 271-277 (Figs. 1-5). 
 
 41. Weinlandia lobata Fuhrmann 1906. 
 See Fuhrmann 1906b: 352-353 (Fig. 1). 
 
 42. W einlandia megalorchis Liihe 1898. 
 See Cohn 1901: 277-280 (Fig. 6-12). 
 
 43. Weinlandia medici (Stossich 1890) Fuhrmann 1906. 
 See Fuhrmann 1906e: 749-750 (Figs. 14-16). 
 
 44. W einlandia microscolecina Fuhrmann 1906. 
 See Fuhrmann 1906e: 740. 
 
 45. Weinlandia magniovata Fuhrmann 1918. 
 See Fuhrmann 1918: 445-447 (Figs. 68-72). 
 
 46. Weinlandia odacantha (Krabbe 1869) Fuhrmann 1906. 
 
 See Krabbe 1869: 301 (Fig. 162) (Taenia octacantha); Fuhrmann 
 1906e: 746-747 (Figs. 9-10). 
 
 47. W einlandia phasianina Fuhrmann 1907. 
 See Fuhrmann 1907a: 533-534 (Figs. 40, 41). 
 
 48. Weinlandia passerina Fuhrmann 1907. 
 See Fuhrmann 1907a: 533 (Fig. 39). 
 
 49. W einlandia parina Fuhrmann 1907. 
 See Fuhrmann 1907a: 534 (Fig. 42). 
 
 50. W einlandia pellucida Fuhrmann 1906. 
 See Fuhrmann 1906c: (Figs. 12-13). 
 
55] STUDIES ON AVIAN SPECIES OF EY M EN LEP I DI DAE—MAY HEW 55 
 
 51. Weinlandia planestici n. sp. 
 See this paper, pp. 73-75. 
 
 52. Weinlandia rostellata (Abildg. 1793). 
 
 See Fuhrmann 1895: 443-449 (Fig. 5-10) {Taenia capitellata Rud.) 
 
 53. Weinlandia simplex Fuhrmann 1906. 
 See Fuhrmann 1906e: 753 (Figs. 20-21). 
 
 54. Weinlandia tetrads Cholodkovsky 1906. 
 
 See Cholodkovsky 1906: 338-339 (Figs. 18-21). 
 
 55. Weinlandia tnbicirrosa Baczynska 1914. 
 See Baczynska 1914: 217-218 (Figs. 49-50). 
 
 56. Weinlandia tenuis Clerc 1906. 
 
 See Clerc 1906a: 536-537 (Figs. 19-21) {Echinocotyle tenuis). 
 
 57. Weinlandia uncinata Fuhrmann 1906. 
 See Fuhrmann 1906c: 441 (Figs. 14-15). 
 
 58. Weinlandia zosteropis Fuhrmann 1918. 
 See Fuhrmann 1918: 441-443 (Fig. 59-63). 
 
 Two testes posterior, the third anterior and median to the 
 antiporal posterior testis. 
 
 59. Weinlandia armata Fuhrmann 1906. 
 See Fuhrmann 1906b: 353-354 (Fig. 2). 
 
 60. Weinlandia coronula (Dujardin 1845) Cohn 1901. 
 
 See Krabbe 1869: 317-318 (Figs. 216-219) {Taenia coronula); Stiles 
 1896: 33 (Figs. 21-28) {Dicranotaenia coronula); Wolfihugel 1900: 
 165-175 (Figs. 97-105) {Dicranotaenia coronula); von Linstow 1905: 5 
 (Figs. 16-18) {E. megalhystera), Fuhrmann 1906e: 733; Meggitt 1920: 
 307-308 (Figs. 1-2). 
 
 61. Weinlandia introversa n. sp. 
 See this paper, pp. 67-70. 
 
 62. Weinlandia interrupta Clerc 1906 (Name preoccupied, see 35 above). 
 See Clerc 1906: 435 (Figs. 5-6). Also listed as 68 below. 
 
 63. Weinlandia macrostrobilodes n. sp. 
 See this paper, pp. 65-67. 
 
 64. Weinlandia microps (Diesing 1850) Fuhrmann 1906. 
 
 See Wolfihugel 1900: 191-192 (Fig. 110); Fuhrmann 1906e: 733. 
 
 65. Weinlandia querquedula Fuhrmann 1913. 
 
 See Fuhrmann 1913: 515-517 (Figs. 103-109). 
 
 Two testes posterior, the third anterior to but varying from a 
 lateral to a median position with reference to the antiporal pos- 
 terior testis. 
 
 66. Weinlandia asymetrica Fuhrmann 1918. 
 See Fuhrmann 1918: 439-441 (Fig. 53-58). 
 
56 ILLINOIS BIOLOGICAL MONOGRAPHS [56 
 
 67. Weinlandia microcirrosa n. sp. 
 See this paper, pp. 70-72. 
 
 68. Weinlandia interrupta Clerc 1906 
 
 See Clerc 1906: 435 (Figs. 5-6). Also listed as 62 above. 
 
 DESCRIPTIONS OF NEW SPECIES 
 
 WEINLANDIA LATERALIS N. SP. 
 [Figs. 55-62J 
 
 The specimen which forms the basis of this description was collected 
 by the writer at San Juan Island, Washington, July 7, 1923, from the 
 intestine of Larus glaucescens Naumann, glaucus-winged gull, and is pre- 
 served in the author's collection under the No. 277 ,1. Its length is 25 cm 
 and its greatest width 1.6 mm. The anterior portion is very much atten- 
 uated, the width just back of the scolex being 100/x, while 100 mm behind 
 it is but 136ju. From this point on, it rapidly increases in size as is indicated 
 by the following measurements: 60 mm from the scolex 220/*, 100 mm from 
 the scolex 765/x, and near the posterior end 1.6 mm in width. There is 
 scarcely any neck since the slight constrictions indicating the beginning 
 of strobilization are evident immediately behind the scolex. The length of 
 the anterior proglottids about equals the width, but after the sex organs 
 begin to develop, the width rapidly increases in proportion to the length, 
 as is indicated by the following figures: at 40 mm behind the scolex the 
 length about equals the width, namely 136/x, at 60 mm behind the scolex 
 where the width is 220^, the length is 170ju; at 100 mm, width 765/x, length 
 255/x; and in the posterior portion where the width is 1.6 mm, the length is 
 0.5 mm. The genital pores are unilateral and on the right side in all 
 portions except at a point about 60 mm from the scolex where there are 
 two proglottids which have the pores on the opposite side. 
 
 The scolex is but little wider than the anterior end of the strobila, and 
 with the suckers, measures but 160/x in diameter. The suckers are round 
 and measure 75/* with an opening 50/z in diameter. The rostellum, which 
 is fortunately fully extended in the single specimen obtained, is relatively 
 large when compared with the scolex proper. It is 250/1 long with a width 
 at the narrowest part of 26/i, and at the distal end of 47/t. The distal end is 
 somewhat dome-like in shape and carries eight hooks which have a shape 
 like figure 55 and which are 26 to 30/x in length. A little below its center 
 the rostellum has a slight constriction which suggests that this is the point 
 to which it is retracted. 
 
 The three testes are all on the poral side of the proglottid, the two 
 nearest the pore are dorsal and on the posterior margin, while the third 
 is somewhat anterior to the median testes and in front of the ovary. The 
 latter is also usually more ventral in position than the other two. Occasion- 
 
57] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 57 
 
 ally proglottids appeared to have four testes in toto mounts, but none were 
 observed in sections to have more than three. Testes are often observed 
 to be lobed in sections and this is believed to account for the appearance 
 of four of these organs in toto mounts. The testes are oval or spherical in 
 shape. They measure about 200ju in length by about 80ju in width in pro- 
 glottids 120 mm from the scolex. 
 
 The vasa efferentia arise on the sides of the testes nearest the external 
 seminal vesicle, and are very slender ducts. Those from the two antiporal 
 testes unite forming a common duct which is soon joined by the duct from 
 the other testes. No irregularities in the vasa efferentia were observed, 
 although it is not at all unlikely that such occur since the organs are so 
 closely packed together in that region it is very difficult to get any clear 
 idea of their arrangement in many proglottids. The vas deferens, thus 
 formed, is short and soon empties into the external seminal vesicle on its 
 inner margin. The external seminal vesicle is a relatively thin-walled sac 
 which lies just in front of, partly dorsal, or partly ventral to the antiporal 
 testis, and communicates with the cirrus sac through a very small pore. 
 The cirrus sac is one of the most conspicuous structures of the proglottid. 
 It extends about half way across the proglottid and has a well developed 
 retractor muscle extending from its inner end to the wall of the proglottid. 
 Two portions are easily distinguishable, even in toto mounts; the innermost 
 portion contains the internal seminal vesicle and the outer portion contains 
 the cirrus. The internal seminal vesicle is rounded and is dividied by partial 
 septa into several almost complete divisions varying in number up to six. 
 These septa seem to disappear as the vesicle becomes enlarged toward 
 maturity, since they are less numerous and even none are present in the 
 proglottids with well developed female organs. 
 
 The cirrus is almost straight but is usually more bent and curved along 
 its inner portion than along the outer. The inner portion is also sometimes 
 expanded into a seminal vesicle-like structure. The inner walls of the outer 
 portion especially are thickly set with stout spines. The cirrus sac opens 
 dorsal to the opening of the vagina, and on the right side of the proglottid. 
 Sections at about 100 mm from the scolex show a direct connection between 
 the cirrus sac and the vagina suggesting that self-fertilization is at that 
 time possible (Fig. 59). However, there are no spermatozoa evident at 
 this time and in fact, there is considerable doubt if any are present in the 
 entire strobila. On the other hand, there are numerous eggs undergoing 
 development, as well as single-celled ova, in the uterus of ripe proglottids, 
 which suggests parthenogenesis. In proglottids with well developed female 
 organs there is no genital atrium as the two pores lie side by side on the 
 surface at the border of the proglottid. 
 
 The vagina, like the cirrus sac, is a conspicuous organ, reaching about 
 one-third the width of the proglottid or about to the inner end of the cirrus. 
 
58 ILLINOIS BIOLOGICAL MONOGRAPHS [58 
 
 The wall of the outer portion is relatively thick, and its inner portion bends 
 ventrally somewhat just medial to the excretory vessels, being rounded 
 and somewhat enlarged. It, like the cirrus sac, passes dorsal to the ex- 
 cretory vessels, and its opening is ventral to that of the cirrus. The median 
 portion of the vagina is a small, somewhat curved duct which passes from 
 the rounded inner end of the thick-walled portion described above, ventral 
 to the testes and dorsal to the ovary to the region behind the antiporal 
 testes where it abruptly enlarges, forming a thin-walled seminal receptacle. 
 A small duct leads ventrally and laterally to its place of union with the 
 oviduct. 
 
 The ovary is deeply divided into eight to twelve finger-like lobes, and 
 lies in the posterior left hand portion of the proglottid. The vitelline gland 
 is likewise deeply lobed, and lies in the concavity in the posterior side of 
 the ovary, while the shell gland is rounded and ventrally placed beneath 
 the vitelline gland. The uterus passes dorsal to the excretory vessels on 
 both sides, and dorsal to the ovary, but ventral to the testes. Its start is 
 found in proglottids about 100 mm from the scolex where its course may 
 be traced by a strand of deeply staining cells. In mature proglottids the 
 uterus extends almost to the margins of the proglottids, and is deeply 
 divided into about a dozen irregular lobes. The eggs are immature. They 
 only consist of an oval mass of cells with readily staining nuclei and a clearly 
 defined outer shell. The shell of the largest egg measured was 21 by 16/u 
 in size, while the smallest was 16 by 12/x. The size of the largest embryo 
 was 16 by 12ju, while the smallest was 10 by llju. 
 
 There are two excretory vessels on either side of the strobila, a large 
 ventral one which measures about 75/x in diameter at about 100 mm from 
 the scolex, and a small dorsal one about 15ju in diameter in the same region. 
 In the anterior and posterior portions of the proglottids, they lie in the 
 central part of the parenchyma about 150^ from the margin. Those on 
 the poral side, however, are displaced ventrally in the central portion of 
 the proglottid by the large cirrus sac and vagina. No connecting vessels 
 could be located in either transverse or frontal sections. The longitudinal 
 muscles are in two layers, each of which contains about 30 bundles on each 
 side of the proglottid. The bundles are very variable in size but those of the 
 inner layer are in general, although not always, larger than those of the 
 outer. 
 
 This specimen seems to be unique when the literature is examined with 
 reference to the arrangement of the testes and ovary. H. ardeae Fuhrmann 
 (1906: 451) has the three testes in a transverse row on the anterior side 
 of the proglottid and the ovary on the side away from the pore beyond the 
 farthest testis. H. elongata Fuhrmann (1906: 450) has the three testes in 
 a transverse row on the poral side but in the posterior portion. The follow- 
 ing species are similar to the above described species in that the three testes 
 
59] STUDIES ON AVIAN SPECIES OF BYMENOLEPIDIDAE—MAYBEW 59 
 
 are all on the poral side of the proglottid: E. setigera (Frolich) 1789, 
 E. venusta Rosseter 1897, E. bilateralis v. Linstow 1905, and E. lanciolata, 
 but no one of them has the antiporal testes placed toward the anterior 
 border of the proglottid. 
 
 Fuhrmann (1908) lists four species of Hymenolepis as occurring in 
 Lariformes. E. fusa was described by Krabbe (1869: 307) from Larus 
 glaucus from Greenland and Larus ridibundus from Bavaria. He records 
 the length as being 250 mm, width 1 mm, 10 hooks 15 to 17/z long, and a 
 few other external details, but as is often characteristic of his descriptions, 
 nothing of the internal structure is given. No record has been found of 
 a restudy of the material, but this could not be our species, since the hooks 
 are only about one-half as long and entirely different in shape. E. basch- 
 kiriensis Clerc 1902, from Larus canus, has hooks 73/j or more than twice 
 as long as our species, and the cirrus sac is much smaller, being only about 
 one-tenth the width of the proglottid, while in the one described above, 
 it is at least one-half the width. E. octacanthoides Fuhrmann 1906 has the 
 testes arranged as in the above description but the ovary and shell gland 
 in the center of the proglottid and anterior to the testes. The fourth 
 species recorded from this group of birds is Weinlandia microsoma which 
 has the testes arranged similar to the above, but the ovary occupies the 
 entire posterior portion of the proglottid ventral to the testes, as described 
 by Cohn (1901: 284). There are ten hooks about twice the size of the W. 
 lateralis. 
 
 WEINLANDIA CYRTOIDES N. SP. 
 [Figs. 85-90] 
 
 The material which formed the basis of the following description was 
 obtained from the intestine of Erismatura jamaicensis, the Ruddy duck, 
 at Peoria, Illinois, on November 26, 1923. These small cestodes were 
 present in large numbers (about 200) in the single host from which they 
 were obtained. They are preserved in the author's collection under the 
 number 576b. 
 
 External Anatomy. This interesting little cestode is from 3 to 10 mm 
 in length, depending upon the stage of maturity and the state of contraction 
 of the specimens. The scolex and rostellum are relatively large for the size 
 of the strobila. The rostellum is about 80/i long with a knob-like distal end 
 60ju in diameter, and a nrrower middle portion 35fj. long. The scolex is 
 about 0.15 mm wide, and has four rounded suckers about 70/x in diameter. 
 The rostellum is armed with eight large dagger-like hooks (Fig. 86), 67 to 
 70/i in length. It is retracted as a solid muscular body and does not seem 
 to be drawn into a sac but only capable of being drawn down toward the 
 scolex, the points of the hooks being drawn down close to its surface. 
 
60 ILLINOIS BIOLOGICAL MONOGRAPHS [60 
 
 Strobilization begins about 0.07 to .1 mm behind the scolex and very 
 soon the strobila is well marked off into distinct proglottids. The proglottids 
 are about 0.07 mm wide at the narrowest part behind the scolex; in the 
 region of the thirtieth proglottid about 0.15 mm; at the fiftieth, 0.2 mm; 
 at the sixtieth, 0.4 mm; and at the eighty-fifth, about 0.4 mm. The number 
 of proglottids in a strobila is about 100, the last one is always sterile. The 
 uterus can be found in about the eightieth proglottid, and from there on 
 gradually increases until in the more posterior ones it occupies almost the 
 entire interior. The beginnings of the testes can be made out in the region 
 of the fiftieth proglottid, and the ovary in about the seventy-fifth. The 
 strobila is usually more or less curved toward the poral side of the chain, 
 depending upon the amount of contraction, due to the unsymmetrically 
 developed ovary and uterus. It may be bent so much that the posterior 
 end extends across the middle of the chain in cases of extreme contraction. 
 
 The three testes are placed so that two of them are on the posterior side 
 of the proglottid and the other in front of the antiporal posterior testes. 
 The position of the anterior antiporal testes varies considerably, but in 
 young proglottids it is invariable anterior and lateral to the posterior 
 antiporal testes. As the cirrus.sac increases in size, it and the mesenchyme 
 surrounding it is usually pushed backward so that the three lie in a trans- 
 verse row. Occasionally a proglottid is found in which it is ventral to the 
 inner end of the cirrus sac and anterior and lateral to other antiporal testes. 
 Still more rarely it lies directly in front of the latter. One proglottid has 
 been found in which only two testes could be identified in a toto mount. 
 The cirrus sac is the first internal organ to appear in the young proglottid, 
 and it shows as a large transverse group of deeply staining cells in the 
 central portion. This develops into the internal seminal vesicle and the 
 inner portion of the sac. Differentiation gradually proceeds outward until 
 the poral side of the proglottid is reached. The walls of the sac are very 
 thick at first and consist of long columnar or almost cuboidal cells which 
 stain very deeply with Ehrlich's acid hematoxylin. As the internal seminal 
 vesicle becomes filled with spermatozoa, these cells gradually lose their 
 staining properties and decrease in size so that the vesicle becomes a thin- 
 walled sac when completely filled with spermatozoa. The internal seminal 
 vesicle, when thus filled, occupies the larger part of the cirrus sac, and has 
 the cirrus attached at its outer end. The cirrus lies along side the internal 
 seminal vesicle (Fig. 88), where it is variously coiled, and finally passes 
 outward to its point of opening upon the surface of the copulatory bulb. 
 The latter is a structure which first appears in young proglottids as a 
 rounded bulb inside the genital atrium, but in old proglottids is found 
 extended through the widely distended pore into a cone-shaped structure 
 from the tip of which the cirrus is extruded. In young proglottids its 
 surface appears to be roughened by circular folds of the clear outer layer. 
 
61] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYEEW 61 
 
 These are not found in the fully extended structure, and seem to be merely 
 a folding in the outer surface to accommodate the large surface to the small 
 space. The cirrus itself is entirely smooth. The pore is on the right hand 
 side of the proglottid. The inner end of the internal seminal vesicle is 
 connected with the external seminal vesicle by a narrow, thin-walled coiled 
 duct. The external seminal vesicle is large, and extends medially and 
 posteriorly into the central portion of the proglottid. 
 
 The first trace of the ovary can be recognized early as a centrally- 
 placed deeply-staining group of cells. As it becomes mature, it comes to 
 lie in two parts, the larger portion consisting of two or three large rounded 
 lobes in the antiporal side of the proglottid and a much smaller poral 
 portion which is generally not lobed. The large antiporal portion may 
 extend considerably beyond the longitudinal excretory vessels, and occupies 
 most of the that side of the proglottids. The vagina opens into the genital 
 atrium, beside the copulatory bulb behind or slightly under the cirrus, and 
 extends medially along the cirrus sac or somewhat beneath. It is a very 
 difficult organ to find on account of its slight differentiation from the 
 surrounding cells, but it may be located even in some proglottids in toto 
 mount. The uterus appears in the region of the eightieth proglottid 
 and rapidly becomes filled with developing ova. In the posterior pro- 
 glottids, it is widely distended, occupying almost the whole of the pos- 
 terior of the proglottid, and is generally somewhat larger in the antiporal 
 side than the poral side of the proglottid. This asymmetrical develop- 
 ment of the ovary and of the uterus causes the strobila to bend toward 
 the pore side when the muscles strongly contract. 
 
 The ova are immature, having but an outer shell, the inner probably 
 being present in some. There are no hooks present. The shell is filled with 
 a loose cellular mass surrounding the embryo which apparently breaks 
 down as maturity is reached. The size of the shell of the largest egg 
 measured was 35/x long and 23/j. wide, while the largest embryo was 30 by 
 14/i in size. The smallest shell was 28 by 19/x and the smallest embryo 21 
 by 14/x. The excretory ducts are ventral to the genital ducts, the larger 
 one is about 5 by 12/x in diameter, while the smaller 5^ in diameter in 
 proglottids where the beginnings of the testes and cirrus sac are well 
 differentiated. They are so crowded and flattened by the excessively 
 developed reproductive glands and organs in the posterior proglottids that 
 they are difficult to identify in cross sections. The longitudinal muscles 
 are well developed, the bundles are about all the same size and the layers 
 are very irregular. 
 
 From the records of specimens which have the testes similarly placed, it 
 is a little difficult to decide to which pattern W. cyrtoides belongs because 
 of the many incomplete descriptions. It was stated hat in the young 
 proglottids the testes were invariably arranged two posteriorly, one on 
 
62 ILLINOIS BIOLOGICAL MONOGRAPHS [62 
 
 each side of the ovary and the other anterior and lateral to the antiporal 
 testes, but in ripe proglottids they usually were found in a nearly transverse 
 row due to the greatly enlarged cirrus sac. Among those which have the 
 testes arranged in a transverse row, one poral and two antiporal, there 
 are none which have a similar combination of internal characters and hook 
 size and shape that are found as described above. In the group having the 
 testes arranged two posterior and the other anterior and lateral on the 
 antiporal side, Weinlandia diorchis Fuhrmann (1913) from Somateria 
 mollissima has hooks that are somewhat similar in shape and length, but 
 the basal portion is much longer in proportion to the blade than in that 
 described above. This species is interesting in that the anterior antiporal 
 testes is small and produces no spermatozoa. 
 
 Among those species of Hymenolepis which have been found in Anseri- 
 formes, the following deserve mention. E. trifolium v. Linstow 1905 has 
 three very small testes located near one another in the center of the 
 proglottid, a cirrus sac reaching only about one-half the width of the 
 proglottid and hooks with a much shorter blade in proportion to the length 
 of the base. H. macrocephala Fuhrmann 1913 has hooks 57 to 63/x while 
 those of this species are about 70p; there the blade and base are about equal 
 in length while in the above described form the blade is much longer than 
 the base. The other worm is also 3.5 to 4 cm long while the specimen 
 described above is but 3 to 10 mm in length. Weinlandia gracilis (Zeder) 
 1803 has the testes arranged much according to the plan of the above 
 description, but they are much larger and the total length of the specimen 
 is 27 cm. The remaining species found in Anseriformes are all much 
 different in internal structure and shape and size of hooks. It seems proper 
 to conclude, therefore, that this species is new. Another species, which is 
 described as bent toward one margin is Weinlandia arcuata Kowalewski 
 1904, a species which has the same general plan of testes arrangement as 
 that herein described, but the cirrus sac and other organs very unlike as 
 well as the hooks. One margin is described as shortened, resulting in the 
 entire worm being bent somewhat ring-like. That the internal structure is 
 the reason for this is not apparent as the organs are symmetrically figured. 
 
 WEINLANDIA CORVI N. SP. 
 [Figs. 79-84] 
 
 The material which formed the basis of the following description was 
 taken from the anterior one-half of the intestine of the common crow, 
 Corvus brachyrhynchos, one host being killed on each of the following dates, 
 May 2. Nov. 3, and 10, 1923, at Monticello, 111. It is preserved in the 
 author's collection under the numbers 203b, 499b, and 531a. 
 
 The specimens of this species are from 30 to 62 mm in length, depending 
 on the maturity of the specimens. Specimens having widely extending 
 
63] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYEEW 63 
 
 uteri filled with ova are about 60 mm long and 0.8 mm wide at the widest 
 point. Proglottids about 25 mm behind the scolex are about 340/x wide, 
 40 mm behind are about 0.7 mm wide, while at the posterior end of the 
 chain they are about 0.8 mm wide. The length and width, of course, varies 
 greatly with the stage of contraction. The various reproductive organs 
 are well developed in following regions; testes 30 mm, ovary 40 mm, and 
 the uterus is well formed at about 50 mm from the scolex. The genital 
 pores are strictly unilateral, and on the right hand side of the proglottids. 
 The scolex is sharply set off from the strobila by being about three times 
 as wide as the strobila immediately behind, it being about 0.15 mm wide 
 when the suckers are well extended, while the strobila just behind it is 0.05. 
 The suckers are rather prominent when extended but when contracted are 
 inconcpicuous and extend scarcely above the surface of the scolex. They 
 are 0.08 mm in diameter on the scolex from which figure 80 was drawn. 
 The rostellum has not been observed in the extended condition, all being 
 more or less retracted. It is retracted as a solid body and not as an introvert 
 as is indicated by the position of the hooks which are outlined in figure 80. 
 There are eight to ten long slender characteristically shaped hooks (Fig. 82). 
 They are 33 to 36ji in length. The basal part is very long as compared with 
 the blade and is usually almost straight but may be either straight or more 
 or less curved. 
 
 Two of the three testes are placed on the antiporal side of the proglottid 
 and one in front of the other. The anterior one is usually directly in front 
 of the posterior, but may be lateral, no instance has been observed where 
 it is medial. The poral testes is in the posterior portion of the proglottid in 
 a line with the posterior antiporal one. The vasa efferentia of three pro- 
 glottids sectioned frontally from the same specimen are shown in figure 4. 
 From these outlines it is observed that they are irregular. The cirrus sac 
 extends considerably beyond the longitudinal excretory vessel. The 
 internal seminal vesicle is relatively small although it occupies somewhat 
 more of the interior of the pouch when fully distended with spermatozoa 
 than is indicated in the early stages (Fig. 83). From its outer end, the 
 cirrus extends in an almost straight line to the opening into the genital 
 cloaca, dorsal to the opening of the vagina. The walls of the cirrus sac 
 and internal seminal vesicle are relatively thick and in some worms the 
 interior contains much loose connective tissue around the vesicle. The 
 genital cloaca is relatively deep. 
 
 The external seminal vesicle is found in the central anterior portion of 
 the proglottid in front of and partially dorsal to the ovary. Its connection 
 with the internal vesicle is through a straight or slightly coiled duct. Well 
 developed testes are to be found in proglottids about 30 mm from the 
 scolex while their first traces are seen much farther anterior to this. The 
 internal end of the cirrus sac is to be found in very young proglottids. 
 
64 ILLINOIS BIOLOGICAL MONOGRAPHS [64 
 
 The ovary is found to be well developed about 35 mm from the scolex, 
 while its start is easily made out 10 mm farther forward. It is divided 
 indistinctly into two portions by being narrower in the region just anterior 
 to the vitellarium. The antiporal portion is somewhat larger and is sometimes 
 slightly lobed, while the poral portion is not lobed or very indistinctly so. 
 The vitelline gland is ventral and somewhat posterior to the ovary and lies 
 about in the center of the proglottid. The vagina opens ventral to the 
 cirrus, and is a wide tube with large irregular shaped cells in its walls. It 
 widens out rapidly medial to the cirrus sac and in old proglottids is found 
 to be a wide sac dorsal to the ovary and completely filled with spermatozoa. 
 The vagina and cirrus sac pass dorsal to the nerve and excretory vessels 
 and the pore is always on the right hand side of the proglottid. The uterus 
 in the posterior proglottids extends well out to the border, but occupies 
 the posterior portion only since the large cirrus sac and external seminal 
 vesicle lie in the anterior portion. The eggs were not found to be mature in 
 any specimen examined. In well preserved material they were only oval 
 or rounded masses of cells with nuclei of varying sizes. In some proglottids 
 the uterus is almost divided into two lateral portions by the large central 
 seminal receptacle. The longitudinal excretory ducts are relatively large 
 and conspicuous, the large ventral one being 50 by 20yu and the smaller 
 10ju in diameter in proglottids about 30 mm from the scolex. The longi- 
 tudinal muscles are irregular in their arrangement, there being numerous 
 small bundles in the dorsal and ventral portions of the proglottids. 
 
 In a discussion of the literature descriptive of cestodes with structures 
 similar to this, the following species deserve mention. In the group of 
 species which have a similar arrangement of testes is H . arcuata Kowalewski 
 1904; here the anterior antiporal testes, however, is lateral to the posterior, 
 the cirrus much smaller, and the hooks, although somewhat similar in 
 shape, are only about half as long as in the above described species. 
 W. importata Fuhrmann 1918 has the hooks very slender and with a short 
 blade but with almost no posterior basal portion, the cirrus sac very small 
 and not reaching the excretory ducts, and the two antiporal testes arranged 
 so that the anterior one is lateral to the posterior. W. interrupta Fuhrmann 
 (1906: 745) has the position of the two antiporal testes described as being 
 one before the other but not otherwise specific. The hooks have a small 
 blade and small posterior basal portion like in the above described species, 
 but the anterior basal portion is much thicker and stronger. Their length 
 is 27^, somewhat under those described above, and the host belongs to the 
 Charadriformes, while the crow belongs to the Passeriformes. W. zosteropis 
 Fuhrmann (1918: 441) from Zosterops minuta, has many similarities, 
 but yet some rather important differences. The cirrus sac is longer and 
 narrower when the figures of ripe proglottids are compared. The ovary is 
 narrower, and considerably lobed, while in the above described form there 
 
65] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 65 
 
 are but few lobes. The testes are smaller (50 to 60/* in diameter as compared 
 with 100/x in the above species) and the anterior basal portion of the hooks 
 is much larger than in the species described above. 
 
 When the literature is examined with reference to the species of 
 Hymenolepis found in Passeriformes, W. pellucida has a somewhat similar 
 arrangement of the testes, but the poral is widely separated from the 
 antiporal, and the hooks, although of a similar length, are not alike in 
 shape. W. magniovata Fuhrmann 1918 has hooks similar in length but not 
 similar to those described above in shape, and the internal structure of the 
 proglottid is very different in that the testes are smaller and widely 
 separated from each other. It seems, therefore, proper to conclude that the 
 species described above is new. 
 
 WEINLANDIA MACROSTROBILODES N. SP. 
 [Figs. 63-71, 78] 
 
 The specimens forming the basis of the following description of this 
 species were taken from the intestine of Anas rubripes, the black duck, one 
 host being taken at Monticello, Illinois on November 3, 1923 and another 
 at Beardstown, Illinois, on November 1, 1923. The parasites are preserved 
 in the author's collection under the numbers 498a and 488a. 
 
 The length of worms with fully developed uterus is about 15 cm, while 
 the greatest width is 2 to 2.5 mm. The strobila is very slender immediately 
 behind the scolex, being usually less tban half a millimeter wide, but 
 rapidly increases beyond the 10 mm point to a maximum 25 mm behind 
 the scolex. The shallow constrictions marking off the proglottids begin 
 to appear about half a millimeter behind the scolex, consequently there is 
 almost no neck. In the older proglottids the posterior border overlaps the 
 anterior portion of the next proglottid a short distance depending upon the 
 state of contraction of the specimen. The genital pores are marginal, on 
 the right hand side, and somewhat in front of the center of the proglottid. 
 
 The scolex is relatively very small when compared with the total length 
 and width of the worm. It is about 125/x, or but little more than 0.1 mm in 
 diameter in the expanded condition. The rostellum is, on the other hand, 
 rather large in proportion to the scolex. It is about 60/i long and 50/jl in 
 diameter at the distal end. The distal portion is somewhat enlarged, and 
 carries a crown of 20 or 21 small hooks. Of the four scolices obtained, the 
 rostellum of one of these had 20 hooks, two of the others had 21, while the 
 fourth was contracted in such a manner that the hooks could not be counted 
 with certainty. The hooks are of the shape indicated in figure 65 and are 
 15 to 16/x in length. The rostellum is retracted into the somewhat shallow 
 rostellar sac as a solid body. The suckers are conspicuous, strongly de- 
 veloped structures with a diameter of about 70,u when expanded. The 
 opening is about 40/i in diameter. They are unarmed. 
 
66 ILLINOIS BIOLOGICAL MONOGRAPHS [66 
 
 In the male system two of the three testes lie on the posterior side of 
 the proglottid, one on each side of the ovary and vitelline gland. The 
 other testis is anterior and median to the antiporal testes. In an exam- 
 ination of 340 proglottids to determine the regularity of the testes, eight 
 were found which either had less than three testes or an abnormal arrange- 
 ment. One of these proglottids had two testes on the poral side and one 
 on the antiporal, all in a transverse row, which is suggestive of an ancestral 
 condition in which there were two or more testes on the poral side, while 
 the occurrence of but one on the poral suggests that possibly the two 
 regularly found there have united. In another there are three on the 
 poral side, two of which are much smaller, suggesting that these have 
 not united. The vasa efferentia arise on the median border of the testes 
 and pass medially. Those from the two antiporal testes usually join, 
 forming a common duct which soon unites with the one from the poral 
 testes just median to the seminal receptacle. The vas deferens, thus formed, 
 is a straight tube, and passes anteriorly and laterally near the median wall 
 of the seminal receptacle to the end of the seminal vesicle. The vasa 
 efferentia were found to be somewhat irregular in their arrangement, as 
 will be seen by examining figures 2 and 3. In some proglottids and in one 
 worm in particular from which their arrangement is shown in 7 consecutive 
 proglottids in figure 2, the vasa efferentia are very irregular. From these, 
 it may be observed that the three main efferentia unite usually as described 
 above, that is, the two from the antiporal testes join before uniting with 
 the poral duct, but in proglottid e, they all three unite at the same point. 
 The number of ducts from a single testes is also seen to be very variable, 
 there being from one to four. In another specimen, the manner of joining 
 of the ducts was found to be irregular, but in the few proglottids that were 
 sectioned, no other irregularities were observed. 
 
 The seminal vesicle is about 0.25 mm long in proglottids 65 mm from 
 the scolex, it having increased from a slender, deeply staining tube in the 
 anterior proglottids to a widely expanded, elongate bulb with the sexual 
 development and the production of the spermatozoa. Its lateral end reaches 
 to the longitudinal excretory vessels, and is joined with the cirrus sac by 
 a slender duct which passes dorsal to the latter and makes one to four coils 
 in the course of this short distance. 
 
 The cirrus sac reaches to the longitudinal excretory vessels and is about 
 3 mm long. A large internal seminal vesicle occupies about half of its 
 length, and early becomes filled with spermatozoa. The cirrus is a very 
 slender thin-walled tube which can only be traced with high magnifications. 
 Its inner portion and sometimes well out to the outer end, has wavy walls 
 which at the narrow' places leave only a very narrow lumen. The outer 
 portion has its wall set with very fine spines. 
 
 In the female system the ovary is placed somewhat ventrally and 
 in the posterior half of the proglottid. It consists of about ten slender 
 
67] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 67 
 
 lobes directed anteriorly and laterally, joined at their bases by a slender 
 portion of the organ. 
 
 The vitelline gland lies posterior to the ovary in the semicircular space 
 bounded anteriorly by the latter. It possesses from four to six rather blunt 
 lobes, and has much the same appearance as the ovary in sections and toto 
 mounts of the younger proglottids but soon can be distinguished from the 
 latter by the smaller nuclei as the ovarian nuclei rapidly enlarge toward 
 maturity. 
 
 The seminal receptacle is about 0.3 mm long, and lies bent around the 
 anterior and median border of the poral testis, its rounded inner end reach- 
 ing almost to the ootype. Its duct is short and uncoiled. The lateral portion 
 lies ventral to the seminal vesicle and reaches almost to the longitudinal 
 excretory vessels, always passing dorsal to the latter, as does the sperm 
 duct, and along the posterior side or somewhat ventral to the cirrus sac to 
 the genital cloaca, into which it opens immediately posterior or somewhat 
 ventral to the cirrus sac. 
 
 The outer shell of the eggs varies in length from 23 to 30/i, and in width 
 from 17 to 28/x, the average size being 21 by 27p. The inner shell, is closely 
 applied to the embryo, and the middle usually so close to the outer that 
 there is no appreciable distance between them, but may be easily dis- 
 tinguished where the middle is folded inward. The embryo is on the 
 average 12 by 23// in size, but varies in length from 17 to 25/*, and in width 
 from 10 to 16ju. The six hooks are about 9/j in length and their shape is 
 represented in figure 66. 
 
 Here as usual the excretory system of the proglottids consists of 
 two longitudinal vessels in each lateral portion about 0.4 mm from the 
 margin. The ventral vessel is much the larger, being about 120/x in diameter 
 while the dorsal is only about 25/i in diameter. The small dorsal vessel 
 curves laterad and mediad much more sharply than the larger, and may 
 be as far out as the middle of the internal seminal vesicle. The larger, on 
 the other hand, lies along the margin of the testes and passes almost 
 invariably under the small sperm duct joining the seminal vesicle and 
 sperm sac. No trace of transverse excretory vessels has been observed 
 either in totos or sections. 
 
 Because of the great similarity between this form and W. inlroversa, 
 the reader is referred to this section in the description of the latter species 
 for a comparison of the organs. 
 
 WEINLANDIA INTROVERSA N. SP. 
 [Figs. 72-77] 
 
 The material which formed the basis of the following description was 
 obtained from the intestine of two specimens of Anas platyrhynchos 
 Linnaeus, the mallard duck, obtained at Peoria, Illinois, November 23 and 
 
68 ILLINOIS BIOLOGICAL MONOGRAPHS [68 
 
 25, 1923, preserved in the author's collection under the numbers 577 and 
 578, and from one specimen of Anas rubripes, the black duck, at Monticello, 
 Illinois, on November 3, 1923, and preserved in the author's collection 
 under the number 498a9. But a single specimen was obtained from the 
 latter host along with several specimens of W. macrostrobilod.es. 
 
 The specimens of this species are much like W. macrostrobilod.es in 
 position of the testes, ovary, and other internal organs, but they can be 
 distinguished with considerable certainty by their smaller size, being only 
 from about one-third to two-thirds as long. The specimens studied were 
 from 50 to 80 mm in length and about 1.5 to 2 mm broad at the widest part. 
 The anterior portion of the strobila is slender, being less than 1 mm wide 
 in the region about 30 mm behind the scolex, but increases rapidly in width 
 and thickness from there on posteriad, the posterior one-fourth to one-half 
 of the strobila being usually of almost uniform width. When the number 
 of proglottids was counted in comparing the position in the strobila where 
 the testes and ovary had reached about the same stage of development as 
 in W. macrostrobilodes, it was found that this point was from 300 to 400 
 proglottids behind the scolex, while in W. macrostrobilodes there were only 
 about 300 in any instance. When the distances were compared, in W. 
 introversa it was found to be about 25 mm from the scolex, depending on 
 the state of contraction, while in W. macrostrobilodes it was 40 to 60 mm. 
 An accurate idea of the comparative width and size of the internal organs 
 may be obtained by comparing figures 68 and 75 which are camera lucida 
 drawings of the same magnification made of the testes and ovary in 
 relatively the same extent of development in the two species. All of the 
 specimens of the two species have been compared with these drawings. 
 
 The scolex shown in figure 73 is about 0.2 mm wide when measured 
 across the extended suckers. The latter are 0.08 mm wide and the rostellum 
 0.05 mm long by 0.07 mm in maximum width. There are 20 hooks 17 to 
 20;ii in length, which have the shape indicated in figure 74. When the hooks 
 are compared in number, size, and shape with W. macrostrobilodes, it is a 
 striking fact that they are almost identical in every way and the one might 
 easily be mistaken for the other, due to the difficulty of observation or to 
 variations. The rostellum is retracted as an introvert. A drawing of a 
 longitudinal section is shown in figure 72, which shows the arrangement of 
 the musculature. There is a bulb-like mass of muscles and connective tissue 
 attached in the central portion of the tip within the crown of hooks. This 
 permits the hooks to be inverted so that their blades are directed outward 
 when the whole is retracted. This is an entirely different arrangement from 
 that found in the scolex of W. macrostrobilodes (Fig. 63). 
 
 In the male system, which has been referred to above, the internal 
 organs are almost identical in position and general structure with those of W. 
 
69] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYEEW 69 
 
 macrostrobilodes except that they are smaller. The three testes are arranged, 
 one poral and the other two antiporal, one of the latter being in front of 
 and median to the other. They are irregularly lobed by slight indentations 
 about their edges, and have the vasa efferentia arising on their median 
 borders. The vasa efferentia pass medially in each instance, the two from 
 the antiporal testes uniting before joining the duct from the poral testes. 
 No irregularities were observed in these ducts although a number of 
 proglottids were examined. It is not improbable, however, that such occur 
 since they are so common in other species. 
 
 The cirrus sac (Fig. 76) contains a large internal seminal vesicle occupy- 
 ing about one-half of its interior when filled with spermatozoa. The cirrus 
 is a narrow structure extending from the outer end of the latter to the 
 opening into the genital cloaca through a mass of cells and muscles. 
 It is somewhat coiled when not extruded. The pore is located on the 
 anterior portion of the margin of the proglottid, and opens into a rather 
 deep narrow genital cloaca with which the cirrus (above) and the vagina 
 (below) communicate. The genital ducts both pass dorsal to the excretory 
 ducts and the pore is always on the right hand side of the proglottid. The 
 external seminal vesicle begins laterally just inside the excretory ducts 
 and reaches to the center of the proglottid. It is an elongated cylindrical 
 sac of about the same diameter when filled with spermatozoa. It is joined 
 to the internal seminal vesicle by a somewhat coiled duct, which in ripe 
 proglottids, becomes expanded in portions into reservoirs for spermatozoa. 
 
 In the female reproductive system the organs are also placed similarly 
 to W '. macrostrobilodes. The ovary is centrally placed between the poral 
 and antiporal testes, and becomes large in ripe proglottids extending about 
 half way across the testes on either side. It is slightly lobed in front, and 
 somewhat curved anteriorly in the center. The vitelline gland is but slightly 
 lobed and lies directly behind the central portion of the ovary. 
 
 The vagina is a thin-walled duct which opens into the genital cloaca 
 ventral to the cirrus and usually lies ventral to the cirrus sac and external 
 seminal vesicle. The portion medial to the excretory ducts becomes dis- 
 tended by spermatozoa in ripe proglottids, forming a seminal receptacle 
 anterior to the poral testes and ventral to the external seminal vesicle. 
 The uterus has the course indicated in figure 69 and described for W. 
 macrostrobilodes. No mature eggs were observed in any specimens. The 
 musculature does not show any marked differences from that as described 
 for and figured for W. macrostrobilodes. 
 
 When the literature is examined with reference to the position of the 
 testes, the following species are to be considered: Weinlandia coronula 
 Dujardin 1845 has the three testes arranged in a similar manner, but they 
 are much smaller in size, the proglottids are much shorter in proportion to 
 the width of the worm than in the above described form, and the testes 
 
70 ILLINOIS BIOLOGICAL MONOGRAPHS [70 
 
 are oval along the transverse axis of the proglottid. The musculature of 
 W . coronula is very characteristic, the two longitudinal layers being very 
 sharply differentiated while in both W. macrostrobilodes and W. introversa 
 there is very little difference in size and location. The hooks are about the 
 same size, shape, and number as in both W. macrostrobilodes and W. intro- 
 versa, but in view of the above points one would have little difficulty in 
 distinguishing the one from the other. Weinlandia querquedula Fuhrmann 
 1913 has a somewhat similar arrangement of the testes as both the latter 
 named, but they are evenly rounded, not lobed, and the antiporal and poral 
 are widely separated from each other, the space in between being occupied 
 by the larger ovary, which extends the full length of the proglottid. The 
 hooks are somewhat similar in shape, the anterior basal portion being 
 somewhat less distinct, however, and the size 14^, and the number 16. 
 
 Of the species which are found in Anseriformes, there are none which 
 compare with these in length and number of hooks except those mentioned 
 above. Of those concerning which nothing is known regarding the hooks, 
 W. lobata Fuhrmann (1906: 352) has a similar arrangement of testes, but 
 widely separated on the two sides of the proglottid and the space between 
 occupied by the ovary. H. megalhystera v. Linstow (1905: 5) has hooks 
 somewhat similar in shape, size, and number, but the testes are arranged 
 in a transverse row. 
 
 WEINLANDIA MICROCIRROSA N. SP. 
 [Figs. 91-97] 
 
 The specimens of this species were obtained from the anterior one- 
 fourth of the intestine of Plancsticus migrator ius (Linnaeus), the robin, 
 killed at Urbana, Illinois, April 4, 1923. They were obtained from three 
 hosts and are preserved in the author's collection under the numbers 112b2, 
 114b4, and 115b2. 
 
 The specimens are 30 to 36 mm long in a very much contracted con- 
 dition. They were found to be most difficult to kill in anything like an 
 extended condition. When allowed to remain in normal salt solution 
 undisturbed, they would relax themselves to two or three times the above 
 length, but when placed in the killing solution, they would immediately 
 contract although attempts to keep them extended by stretching with the 
 fingers or by shaking were made. When held extended in the fingers, they 
 very readily pulled themselves in two in their efforts to contract. The only 
 method tried that was even partially successful was to allow the worm 
 to extend itself on a glass slide, and to quickly place another slide over it 
 binding the two together with rubber bands, in which condition they were 
 placed in the killing fluid. This resulted in specimens that were much 
 contracted and in some instances poor fixation of the internal structures. 
 Specimens killed in this manner were about 2 mm wide at their widest point 
 
71] STUDIES ON AVIAN SPECIES OF EYMENOLEPIDIDAE—MAYHEW 71 
 
 and 30 to 36 mm long. In life they are capable of extending to two or three 
 times -this length. 
 
 The scolex of the specimen from which the drawing was made is 0.1 mm 
 wide, and has the four suckers directed forward in the contracted state. 
 There is no neck region, since strobilization can be made out along the 
 border at the widest portion of the chain opposite the rostellar sac. Behind 
 this point, the strobila rapidly narrows to about one-half the above width 
 and then gradually widens again. In one specimen, the scolex is but little 
 wider than the anterior portion of the strobila. The rostellum is retracted 
 into the rostellar sac in all the specimens studied, and is about 0.2 mm in 
 diameter, evenly rounded and bears a single crown of ten hooks which are 
 shaped like figure 93, and are about 12/x long. 
 
 In the male reproductive system the three testes are placed two in the 
 posterior portion, one on either side of the ovary and the other in front of 
 the antiporal posterior testes. The latter may be medial to, directly in 
 front of, or lateral to the posterior antiporal testis. They vary much in 
 size, but in specimens fixed in the partially contracted condition, they are 
 about 200 by 85^, being longest in the transverse axis of the strobila. Their 
 ducts arise on the median border in each case. Occasionally there are two 
 from a testis, but usually only one, and pass in an almost straight course 
 to their point of union. The manner of union is variable as indicated by 
 the drawings of four consecutive proglottids in figure 1. The vas deferens 
 is short and connects with the external seminal vesicle which lies in front 
 of the ovary in the right half of the proglottid. The external seminal vesicle 
 is connected with the internal seminal vesicle by means of a duct which 
 is gradually tapering laterally. The cirrus sac (Fig. 96) extends somewhat 
 beyond the excretory ducts, and the larger part of its interior is occupied 
 by the internal seminal vesicle. The walls of the vesicle and sac are rather 
 heavy, and wide circular ridges along their sides are seen in cross section. 
 These are more prominent in the outer half than the inner. The cirrus 
 is short, straight, and spineless, and opens just dorsal to the vagina into 
 the shallow genital cloaca. The pore is situated about one-fourth of the 
 way back on the right hand margin of the proglottid. 
 
 In the female reproductive system the ovary is a deeply lobed trans- 
 versely elongated organ located in the center of the proglottid. The 
 vitelline gland lies just behind it and the vagina comes in from the right 
 and anteriorly at about the middle of the proglottid. The seminal receptacle 
 lies ventral to the external seminal vesicle, its inner end sometimes bending 
 posteriorly around the poral testes. It communicates with the genital 
 cloaca through a long, slender, straight vagina which lies directly ventral 
 to the cirrus sac and opens almost directly ventral to the cirrus. 
 
 The eggs in the uterus have three shells with the six-hooked embryos 
 within. The two outer shells are very thin and often much distorted by 
 
72 ILLINOIS BIOLOGICAL MONOGRAPHS [72 
 
 shrinkage. The average length of the outer is 45/t and width 40/i, with a 
 maximum of 54 by 45ju, and a minimum of 42 by 31/x. The middle shell 
 averages 40pi in length and 31ju in width with a maximum length of 42/x 
 and a width of 39/jl, and a minimum length and width of 33/jl and 23^. 
 The embryo averages 38 by 25/* and has a maximum of 35 by 38/j, and a 
 minimum length and width of 31 by 21/x. The hooks are 17 to 20/x long. 
 
 The longitudinal muscle layers are well developed, especially the outer 
 one. The inner contains a much less number of bundles. The oblique 
 muscles are very poorly developed, and in most proglottids none were 
 found except in the outer angles. The regions separating the proglottids 
 are clearly defined. 
 
 The large ducts of the excretory system are about 0.15 mm in diameter 
 and the small dorsal duct about 0.05 mm in diameter, 1 cm from the scolex. 
 No transverse vessels joining either of the longitudinal vessels could be 
 traced. 
 
 The longitudinal nerve lies about 0.15 mm from the margin of the 
 proglottid and under a point about one-fourth the length of the cirrus 
 sac from its outer end. 
 
 When the descriptions of the various species are compared with the 
 above description with reference to the position of the testes, the following 
 deserve mention: Weinlandia lobata Fuhrmann (1906: 352) has the testes 
 arranged in a similar position, and the cirrus sac is much like the one 
 described above, but the onchosphere is 16ju in diameter, while in our 
 species it averages 25 by 38jii. The scolex was absent from Fuhrmann's 
 specimens but the length of the strobila is 14 cm, while the above described 
 specimens were not over 8 cm long when fully extended, and but about 
 35 mm when fixed. H. minor (Krabbe) 1869 has hooks similar in shape 
 and length but 14 in number. It is 25 mm long, and was found in Phalaropus 
 hyperboreus (Linn.) a bird belonging to the Charadriiformes, while the 
 robin belongs to the Passeriformes. H. minor is so poorly described that 
 it ought to be disregarded as a species unless the original material can 
 be restudied. 
 
 When compared with the species of Hymenolepis that have been 
 recorded from the Passeriformes, there are only three which have similar 
 hooks. H. bilharzii Krabbe 1869 has hooks that are much more strongly 
 constructed in all parts and 16/i long. It is so poorly described that it 
 must probably be disregarded. H. palygramma (von Linstow) 1875 has 
 hooks 17m long and was described from immature material having no sex 
 organs. Weinlandia importata Fuhrmann 1918 has hooks 12 to 16/x long, but 
 they are very slender and have a very long anterior basal portion and 
 almost no posterior basal portion. There seems little doubt, therefore, that 
 the above described species is new. 
 
73] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 73 
 
 WEINLANDIA PLANESTICI N. SP. 
 [Figs. 98-103] 
 
 The cestodes used in the study of this species were obtained from 9 
 specimens of Planesticiis migratorius, robin, killed at Urbana, Illinois, 
 between April 1 and May 1, 1923. They were taken from the middle 
 three-fourths of the intestine and were found either attached to or free 
 from the intestinal wall. The specimens are preserved in the author's 
 collection under the numbers, 104, 105, 106, 108, 113, 114b, 123b, 125, 
 174b. Of this species cotypes were placed in the Ward Helminthological 
 Collection at the University of Illinois, Urbana, nine mounts, comprising 
 five totos and four sets of serial sections. 
 
 The specimens vary in length from 10 mm to 35 mm, and in width from 
 0.5 to 1.5 mm, depending on the stage of contraction and maturity of 
 the worm. One specimen with mature eggs measured 20 mm long and 
 1 mm wide near the posterior end. 
 
 The scolex in all the specimens was strongly contracted and was about 
 0.2 mm broad, depending on the size of the worm. The suckers are strongly 
 contracted, and are not raised appreciably above the surface of the scolex, 
 the opening being directed forward. The rostellum is a strong muscular 
 structure which is retracted into the rostellar sac as a solid muscular organ, 
 and not as an introvert, the blades of the hooks always being directed 
 backward. The rostellum carries a crown of ten hooks which have the 
 shape represented in figure 101 and a length of about \Ajx. Strobilization 
 is evident immediately behind the scolex. 
 
 In the male reproductive system two of the three testes are placed on the 
 posterior side of the proglottid, one poral and the other antiporal, and the 
 third in front of the antiporal one. The latter is usually directly in front 
 of the posterior testes, but in some specimens especially, its position varies, 
 being placed either somewhat medially or laterally. The vasa efferentia 
 are very variable in this form, as is indicated by the various figures. The 
 number arising from each testes varies from 1 to 3, any testes may have 
 any number up to three. Neither do the ducts pass directly to their point 
 of union but may curve about and be joined by short ducts with each 
 other giving the appearance of a network. Invariably, however, the ducts 
 from the two posterior testes join before meeting those from the anterior 
 testes. The testes are 0.06 to 0.08 mm in diameter in the region where the 
 ovary and other female organs are well developed. 
 
 The vas deferens is a comparatively short duct. The external seminal 
 vesicle communicates with the internal seminal vesicle through a short, 
 usually somewhat coiled, duct. The internal vesicle is a simple sac, its inner 
 portion being considerably larger than the outer and occupying about 
 three-fourths the length of the cirrus sac. The cirrus is a slender tube and 
 
74 ILLINOIS BIOLOGICAL MONOGRAPHS [74 
 
 is but slightly coiled, opening into the genital atrium dorsal to the opening 
 of the vagina. Both the vagina and cirrus sac pass dorsal to the excretory 
 vessels and the nerve, the large end of the cirrus sac lying directly above 
 them. The pore is to be found slightly in front of the center of the pro- 
 glottid, exactly on the margin, and on the right hand side. 
 
 In the female system the ovary lies in front of the two posterior testes 
 and somewhat ventral to them. It is an elongate structure with irregular 
 fan-shaped lobes on the anterior border. The vitelline gland lies behind it 
 and is a rounded or oval organ without lobes. The seminal receptacle lies 
 ventral to or somewhat posterior to the external seminal vesicle, and is 
 very variable in shape, but generally elongated or oval in outline. The 
 vagina is a long, wide, straight duct extending from the outer end of the 
 seminal vesicle to its opening ventral to the opening of the cirrus in the 
 genital atrium. 
 
 The eggs are very irregular in shape, due to shrinkage of the outer 
 shells. The shells are very thin and the two outer have the space between 
 them filled with material which is probably a loose cellular mass in the 
 process of disintegration, while the space between the middle and inner 
 shells is clear. The average size of the outer shell is 47 by 35/i, with a 
 maximum length of 56/i, and a maximum width of 42/j. It has a minimum 
 length of -il/jL and a minimum width of 28/x. The average length of the 
 inner shell is 38ju and the average width 27fi, its maximum length and 
 width being 44 and 33/jl respectively and its minimum 33 and 23/x. The 
 embryo has an average size of 32 by 24/x, a maximum length and width 
 of 40 and 30ju, and a minimum length and width of 28 and 19yu. 
 
 The inner longitudinal muscle layer contains about 25 bundles on each 
 side of the proglottid, while the outer layer contains about 50 bundles. 
 
 The dorsal excretory vessel is somewhat smaller than the ventral, being 
 about 18ju in diameter, while the other is about 23 to 25^ in diameter. 
 Transverse vessels joining the longitudinal vessels have not been found. 
 
 A comparison of the above species with others necessitates a discussion 
 of the following: W. farciminosa (Goeze) 1782, has hooks similar in shape, 
 but 20 to 23/j. long, while in the above they are 14yu long. Rosseter's (1908: 
 295) discussion of this species shows that the material which has been 
 referred to it is in need of restudy since but little attention has been given 
 the internal organs by most of the investigators, and Rosseter gives figures 
 of the hooks from four sources which vary in shape. It is not possible to 
 determine whether the material which Rosseter examined was identical 
 with that of all the others or not on account of the incompleteness of the 
 other descriptions. Fuhrmann (1908, footnote 4, p. 79) gives a discussion 
 of its synonomy. 
 
 Of the species which have been described from Passeriformes whose 
 size of hooks are near that of the above described form, the following should 
 
75] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 75 
 
 be mentioned: H. petrocinclae Krabbe 1882 has hooks lS^u long, but very- 
 different in shape; H. polygramma (von Linstow) 1875, length 17//, but the 
 two lateral testes are lateral to the longitudinal excretory vessels according 
 to Fuhrmann (1906: 734). II. bilharzii (Krabbe) 1869 has the blade shorter 
 than the base, and the anterior portion of the base shorter than in the 
 above described form; Weinlandia serpentida (Schrank) 1788, has hooks 
 24 to 27/x long, almost twice as long as in the form under discussion and 
 a much longer and heavier anterior basal portion. Ransom (1909: 96) 
 records this form from Planesticus migratorus with a question mark, but 
 the reference which formed the basis for this statement is not given and 
 has not been located during the present study. Fuhrmann 1908 does not 
 include the name of the host in his list of cestodes under their hosts. It 
 seems clear, then, that the form just described should be designated as a 
 new species. 
 
76 ILLINOIS BIOLOGICAL MONOGRAPHS [76 
 
 GENUS WARDIUM NOV. GEN. 
 
 Diagnosis: Three testes in a proglottid. Position of the testes in the 
 different proglottids of the strobila variable. Scolex armed with a single 
 crown of hooks. Genital pores unilateral. Uterus sac-like. Genital ducts 
 dorsal to the excretory canals. 
 
 Type species: Wardiiun fryei n. sp. 
 
 WARDIUM CAPRIMULGORUM (FUHRMANN) 190.6 
 
 Fuhrmann 1906c: 441 (Figs. 16-19); 1906e: 740. 
 
 Syn. : Drcpanidotaenia caprhmdgorum Fuhrmann 1906c, 
 
 Hymenolepis caprimulgorum Fuhrmann 1906e. 
 Hosts: Nyctiprogne rupeslris (Spix), Podager nacunda Cab. 
 
 Caprimulgus linealus. 
 Locality: South America. 
 
 Through the courtesy of Dr. Anton Collin, Director of the Zoologisches 
 Museum der Universitat, Berlin, Professor Ward received alcoholic 
 material representing this species which was sent on loan and proved very 
 valuable. For this courtesy the author desires to acknowledge here his 
 indebtedness to the Museum and its Director. 
 
 Length 12 cm, width 1.5 mm. Testes variable in position. Cirrus sac 
 small, not reaching the longitudinal excretory ducts. An internal and an 
 external seminal vesicle present. Fuhrmann did not have any scolices when 
 he first described the species, but he afterward found some and gives their 
 description in 1906e: 740. They are 0.14 mm in diameter, and the rostellum 
 is armed with 10 hooks which are 14/* in length. 
 
 WARDIUM CAPILLAROIDES (FUHRMANN) 1906 
 
 Synonym: Hymenolepis eapillaroides Fuhrmann 1906. 
 
 Fuhrmann 1906b; 355. 
 
 Hosts: Podiceps dominicus (L.). 
 
 Locality: Brazil. 
 
 Alcoholic material representing this species was sent from the Zoolo- 
 gisches Museum der Universitat, Berlin, through the Director, Dr. Anton 
 Collin, to the Ward Helminthological Collection at the University of 
 Illinois, Urbana, and was placed at the disposal of the author who is greatly 
 indebted for these courtesies. 
 
 Length 3 cm, width 0.4 mm. Scolex 0.1 mm in diameter. Hooks are 
 10 in number and 21/j. long. Cirrus sac reaches beyond the longitudinal 
 
77] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 77 
 
 excretory vessels but not beyond the center of the proglottid. The testes 
 are arranged so that all three may lie in a transverse row or the antiporal 
 testes somewhat anterior to or in front of the median testis. Ovary and 
 vitelline gland median and small in size. Uterus sac-like and fills the entire 
 interior of the proglottid. 
 
 Southwell (1916:10) found several specimens of a cestode in Corvus 
 macrorhynchos, a crow, at Calcutta, which he thinks possibly are Wardium 
 capillar -oides. This material should be restudied since the testes were 
 observed to be regular in position, the posterior proglottids were square, 
 and the details concerning the hooks could not be determined with cer- 
 tainty. The wide difference in the hosts is further indicative of different 
 species. 
 
 WARDIUM AMBIGUUM (CLERC) 1906 
 
 Synonym: Eymenolepis ambiguus Clerc 1906. 
 Clerc 1906a: 535. 
 Host: Otis telrax. 
 
 Length 120 mm, maximum width 0.7 mm. Scolex 0.22 mm in diameter. 
 Hooks 10 in number 30// in length. Genital pores unilateral, and the 
 genital ducts pass above the excretory vessels. Cirrus sac 0.18 mm long. 
 External and internal seminal vesicle present. The only statement relating 
 to the position of the testes is that they are variable according to the state 
 of contraction of the strobila. There is, therefore, some uncertainty as to 
 the exact genus to which this species should be placed. It should be 
 restudied in order to determine its exact relationships. 
 
 WARDIUM VARIABILE N. SP. 
 [Fig. 17-23] 
 
 Two specimens of this species were taken from the intestine of a 
 specimen of Corvus brachyrhynchos, the common crow, killed at Monticello, 
 Illinois, on November 10, 1923, and are preserved in the author's collection 
 under the numbers 530.1 and 530.2. The length of one is 30 mm and its 
 greatest width is about 1 mm near the posterior end. The other specimen 
 is 20 mm long and 0.7 mm wide at its widest point. They each contain 
 about 250 proglottids, of which the anterior 100 or so are very short in 
 proportion to their width. Behind this point the reproductive organs 
 rapidly develop, the testes first and the female farther back. 
 
 The scolex is conspicuous, being much wider than the anterior end of 
 the strobila. It is about 0.2 mm wide or slightly less, while the width of 
 the neck region is 0.06 mm. The suckers are 0.08 mm in diameter, and 
 somewhat raised above the surface of the scolex. The rostellum was 
 retracted in both specimens, in which condition it is a rounded organ about 
 
78 ILLINOIS BIOLOGICAL MONOGRAPHS [78 
 
 0.02 mm in diameter. It is armed with a single crown of hooks which 
 measure from 20 to 22/x in length. The base is much curved and for this 
 reason the shape of the hook may be easily misjudged unless one is careful 
 to observe one which lies with all its parts as nearly as possible in the same 
 plane of focus. 
 
 The testes are regularly three in number, although four proglottids 
 were found out of 102 which had four each and one had but two. Their 
 arrangement in 67 of the 102 cases was two on the posterior border and one 
 antiporal and lateral to the posterior antiporal testes. Four had the 
 anterior antiporal testis in front and one medial to the posterior antiporal 
 testis, while eleven proglottids had the three organs in a row on the posterior 
 border. In nine instances the two lateral testes were both anterior to the 
 median which was on the posterior border of the proglottid; in five pro- 
 glottids two were poral, one testis being anterior and lateral to the posterior, 
 and but one instance was found where two only were observed, they being 
 on the antiporal side. 
 
 The cirrus sac extends medially about one-third the width of the pro- 
 glottid and in each instance observed contained a relatively small internal 
 seminal vesicle. However, the latter was not observed distended with 
 spermatozoa. It is thick walled and has a layer of small nuclei about its 
 outer margin. The cirrus extends from the outer end of the internal 
 seminal vesicle outward and extends through about two-tbirds of the 
 length of the sac. It opens into the genital cloaca dorsal or anterior to 
 the vagina. The genital cloaca is a wide rounded cavity up into which an 
 elevation of the surrounding tissue of the proglottid extends. The pore is 
 to be found about one-fourth the way back on the right hand margin of the 
 proglottid. The external seminal vesicle lies directly in front of the vitelline 
 gland and ovary, the latter extending beneath it when reaching maturity. 
 
 The ovary lies in the anterior ventral portion of the proglottid, beneath 
 the external seminal vesicle and the vagina. It is divided by deep con- 
 strictions on the anterior side into several lobes up to about six in number 
 which extend anteriorly and laterally in a fingerlike manner. The whole 
 organ is somewhat bent anteriorly in the center, and has the vitelline gland 
 and shell gland placed in the posterior concavity. When fully developed, 
 it extends somewhat farther laterally than shown in figure 22a, but never 
 reaches to the excretory vessels. The vagina lies beneath or slightly 
 posterior to the cirrus sac and is a rather thick-walled duct which widens 
 out at its inner end to form a seminal receptacle dorsal to and behind the 
 ovary. The vitelline gland is a spherical or oval organ lying just behind 
 the ovary. Between the ovary and vitelline gland or slightly more ventral, 
 the shell gland is to be found. The uterus is a transverse sac which is 
 irregularly divided by partial septa into several lobes. The eggs were present 
 in large numbers, but in neither of the specimens obtained were they 
 
79] STUDIES ON AVIAN SPECIES OF BYMENOLEPIDIDAE—MAYBEW 79 
 
 mature. A few large single cells were observed which apparently were 
 unfertilized eggs and consequently had not developed. 
 
 The ventral longitudinal ducts are considerably larger than the dorsal, 
 as is usual in this group of cestodes, being about 35 by 25/x in diameter, 
 while the dorsal are 14ju in diameter. The large ventral vessels are connected 
 by transverse vessels 7n or wider in diameter, while no such connections 
 occur between the dorsal vessels. Occasionally these transverse vessels 
 are branched at the end (Fig. 23). The longitudinal nerve lies on each 
 side usually about half way between the excretory vessels and the border 
 of the proglottids. The longitudinal muscles are differentiated into two 
 well defined and widely separated layers (Fig. 17). The inner one contains 
 about a dozen bundles on a side. The outer contains about 20 to 25 bundles 
 which are about 5p in diameter while the inner are about 12ju in diameter. 
 
 A discussion of this species with reference to the literature is indeed 
 difficult when considered with reference to the position of the testes. One 
 of the most satisfactory descriptions of a species with testes variable in 
 position is that of W. caprimidgorum Fuhrmann (1906c: 441), collected 
 in Brazil from Nactiprogne riipestris, Podager nacunda and Caprimulgus 
 lineatus. The most outstanding differences are, however, the very small 
 cirrus in W. caprimidgorum , where it reaches only about half way to the 
 excretory vessels on the poral side, and the hooks which are 14ju long, 
 while in the above described form they are about one-third longer, the 
 anterior portion of the base being much shorter than in that described 
 above. The difference in the orders of birds to which the hosts belong is 
 also marked, that of W. caprimidgorum being Coraciiformes while the 
 crow to the Passeriformes. Another species which is recorded as having 
 testes variable in position is that cf W. capillaroides Fuhrmann 1906, but 
 in this the testes are smaller and the two on the antiporal side are some 
 distance removed from the poral testes, the pore is in the center of the 
 proglottid, while in the above described form it is only one-third the way 
 back on the border. The hooks, although of about the same size, are more 
 slender in structure throughout while the host oiW . capillaroides is a grebe. 
 
 When the literature is examined with reference to the species that have 
 been recorded from the Passeriformes, it is found that there are, in all, 
 24 species. When the size of the hooks from these various species are com- 
 pared, it is found that only those species included in the following com- 
 parative table agree near enough in size to be considered. In the following 
 table some of the important characters are compared with the species 
 described above. 
 
 From the following table one sees that the hooks of W. variabile differ 
 in shape from those of the other species infecting Passeriformes which 
 have hooks of a similar length. Four of the species have the location of 
 the testes very inadequately described and no statement is made as to the 
 
80 
 
 ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 Position of testes 
 Wardium variabile 67% Variable 
 
 TABLE I 
 
 Comparison of Somewhat Similar Species 
 
 Shape of hooks 
 
 Size of hooks 
 Blade and 2 parts of base 20 to 22 m 
 about equal 
 
 H. hemignathi 
 
 Transverse row 
 
 Blade very long 
 
 18 to 23 m 
 
 II. pelrocindae 
 
 ? 
 
 Anterior portion base very 
 long 
 
 18 /i 
 
 W. passerina 
 
 2 antiporal 1 before the 
 
 Ant. portion base very long, 
 
 20 m 
 
 
 other 
 
 blade and post, portion 
 base very short 
 
 
 W. interruptum 
 
 2 antiporal 1 before the 
 
 Ant. portion of base much 
 
 20 m 
 
 
 other 
 
 longer than post and blade 
 
 
 W. microscolecina 
 
 2 antiporal 1 in front of 
 
 Blade and 2 parts of base 
 
 23 m 
 
 
 other 
 
 about equal but ant. por- 
 tion of base much heavier 
 than in above described 
 
 
 
 
 form 
 
 
 W . farciminosuni Straight line? 
 
 W. serpentulum 
 
 W. globocephalum 
 
 2 poral, 1 before other, 
 separated from other pos- 
 terior 
 
 2 antiporal, 1 in front of 
 other, but small and sep- 
 rated far from poral testes 
 
 Both parts of base much 
 heavier than in above de- 
 scribed form 
 
 21m 
 
 Post, part of base very 25 to 27 m 
 heavy 
 
 Very heavy in structure in 
 all parts 
 
 19 m 
 
 variability of their position in any of the descriptions. No records are 
 given by Fuhrmann (1908) of any cestodes from any of the species of crow 
 in North America. It seems quite clear then that this species is new. 
 
 WARDIUM FRYEI N. SP. 
 
 [Figs. 24-3 1J 
 
 The material from which this description was written was obtained 
 from the intestine of a specimen of Larus glaucences, the glaucous-winged 
 gull, killed in San Juan county, Washington, July 20, 1923, and is pre- 
 served in the collection of the writer under the number 276. 
 
 The specimens are very slender cestodes which measure 115 mm in 
 maximum length but do not exceed 1 mm in width at their widest point. 
 The anterior 25 to 30 mm is very slender, and disintegrates very early 
 after the death of the host. The male sex organs are well developed in 
 
81] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 81 
 
 proglottids 20 to 30 mm from the scolex, and the beginning of the female 
 organs is well differentiated. It should be noticed especially at this point 
 that the start of the ovary in the early stages and the fully formed organ 
 may be very easily confused with the testes and therefore it is only possible 
 to identify these organs with certainty from sections. Frontal sections 
 are the most useful as the ovary is ventral and is not obtained to any great 
 extent in sections containing the testes. Because of the great variability 
 of the position of the testes, these organs cannot be identified by their 
 location as they can in species characterized by regularity of position. 
 Proglottids about 50 mm from the scolex are about 0.35 mm in transverse 
 diameter by 0.2 mm in thickness, while at the extreme posterior end they 
 are usually less than 0.8 mm wide. The pore is unilateral and on the right 
 hand side of the proglottid. 
 
 The scolex is somewhat larger than the strobila immediately behind, 
 it being about 106/x while the strobila is about 70^ in width. The rostellum 
 is short, rounded, and armed with a single crown of ten hooks. But three 
 scolices were obtained, from two of which the hooks had been lost. The 
 other had ten hooks, 17 to 19/x long, shaped like figure 26. The rostellum 
 was not retracted, although there was a deep rostellar sac extending as 
 far back into the scolex as the posterior border of the suckers. In so far as 
 it could be made out, the rostellum seemed to be retracted as a solid organ 
 and not as an introvert. 
 
 The three testes are placed in an irregular manner, the proglottids in 
 which they are placed in an almost transverse row are somewhat more 
 numerous than are those with the other arrangements. They may, however, 
 be placed so that two are on the posterior side and the other directly in 
 front or somewhat lateral to either the poral or antiporal testis, or one may 
 be median and posterior and the others one on either side and somewhat 
 anterior to it. Of 169 proglottids examined, of which about an equal 
 number were counted for each of four specimens, the testes were dis- 
 tributed as follows: 45 had all three in a row; 55, one was posterior and one 
 on each side and anterior to it; 50, two posterior and the other anterior or 
 lateral to antiporal testes, and 19 in which two were posterior and the 
 other anterior or lateral to the poral testes. The testes are crowded ven- 
 trally or dorsally, or indented by the cirrus sac and external seminal vesicle, 
 depending upon the stage of development of the organs, the ripe pro- 
 glottids being very well filled in the central portion by reproductive organs. 
 The cirrus sac is very large and occupies the anterior half of the poral side 
 of the proglottid, opening into the genital cloaca which lies on the right 
 hand side of the proglottid a little in front of the center of the border of the 
 proglottid. It appears very early and soon comes to contain the very large 
 cavity of the internal seminal vesicle, which occupies the larger part of 
 the interior, and almost fills it when filled with spermatozoa. The cirrus 
 
82 ILLINOIS BIOLOGICAL MONOGRAPHS [82 
 
 is a thick fleshy organ, the duct of which is thin walled and much coiled 
 in the unextruded organ. It opens into the internal seminal vesicle at the 
 outer end of the latter. What appears to be the cirrus when extruded is 
 seen to contain numerous small nuclei and to be made up of loose connected 
 tissue, the outer surface being entirely free from hooks or spines (Fig. 10). 
 The external seminal vesicle is a large thin-walled sac which lies just 
 medial to the inner end of the cirrus sac and communicates with it through 
 a short, wide, somewhat coiled duct. The external seminal vesicle and 
 cirrus sac together reach a little more than half way across the proglottid 
 in most cases. 
 
 The ovary (Fig. 28) is an irregularly lobed organ lying posteriorly in 
 the proglottid and ventral to the testes, the anterior portion of the pro- 
 glottid being occupied by the cirrus sac and external seminal vesicle. The 
 vagina lies directly ventral to the cirrus sac and opens into the genital 
 cloaca ventral to the cirrus (Fig. 22). It is a clearly defined, heavy-walled 
 duct somewhat coiled and widens out forming the seminal receptacle which 
 lies just ventral to the inner end of the cirrus sac. The vitelline gland is 
 irregularly rounded or oblong, and lies dorsal and anterior to the ovary and 
 ventral to the testes and cirrus sac. 
 
 The uterus is a transverse sac divided incompletely into compartments 
 by septa and well filled with eggs in the mature proglottids. The embryos 
 are oval in shape and average 34 by 28/x in size but range from 28 to 40^ long 
 by 23 to 4<V wide. Figure 25 represents about an average shape but they 
 are often more elongate or more rounded. The outer shell ranges in 
 diameter from 37 to 52/u by 26 to 49p and averages 26 by 37/x. The inner 
 shell is closely applied to the embryo, but two shells could be made out on 
 any of the eggs. Although the hooks are well developed and apparently 
 fully formed, no trace of the middle shell could be found. Ransom found 
 a somewhat similar condition in the eggs of Hymenolepis cantaniana,- 
 differing however, in that the contents of the egg of the latter is separated 
 into two regions separated by a very thin membrane. The hooks are often 
 found extending through the outer shell, and are very prominent, having 
 a characteristic enlargement on the shaft about three-fourths the distance 
 from the inner end. This enlargement in many appears to go entirely around 
 the shaft while in others this is not apparent. The hooks are from 14 to 
 17.5/x in length, and great care must be used in selecting those to be 
 measured in order to have the entire hook as nearly in the same plane of 
 focus as possible. 
 
 It is difficult to make a comparative study from the literature of the forms 
 known to show variability in the position of the testes. Earlier workers 
 apparently failed to appreciate the possible importance of recording such 
 variations in an exact manner. Fuhrmann seems to be almost the only 
 investigator who has taken any notice of this fact, and has described two 
 
83] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 83 
 
 species as having this peculiarity. These are W. caprimulgorum Fuhrmann 
 1906 and W. capillaroides. Aside from the great difference in the hosts, 
 the hooks are very different in shape, in that they both have well-developed 
 anterior basal portions, while the above described species has none at all. 
 W. ambiguum Clerc 1906 has testes somewhat variable in position but the 
 hooks are almost twice as long, and it has a long anterior basal portion. 
 E. clandestina (Krabbe) 1869 is the fourth species to which reference has 
 been made to the testes being in a variable position, but here again the 
 hooks have a long anterior basal portion and are twice as long as in the case 
 of the above described form. 
 
 Five species of Hymenolepis have been recorded from the Lariformes. 
 All five of them have hooks very different in shape, or of a different number, 
 from those in the species first described, as well as other characters. It 
 seems proper to conclude that the above described species should be 
 designated as new. 
 
84 ILLINOIS BIOLOGICAL MONOGRAPHS [84 
 
 GENUS ECHINORHYNCHOTAENIA FUHRMANN 1909 
 
 Generic diagnosis: Genital pores unilateral. Genital ducts pass between 
 the longitudinal excretory vessels. Testes three in number. Uterus sac-like. 
 Rostellum proboscis-like and covered with hooks. 
 
 Type species: Echinorhynchotaenia tritesticulata Fuhrmann 1909. 
 
 This genus was erected by Fuhrmann to accommodate E. tritesticulata 
 and placed in the family Dilepinidae. The number of the testes in the two 
 species thus far assigned to it, however, is believed to justify its transfer 
 to the family Hymenolepididae. The internal anatomy is indeed similar 
 to that found in the genera Wardium and Hymenolepis, but in view of 
 the constancy of the position of the genital ducts with reference to the 
 excretory ducts in the species studied and the probable systematic im- 
 portance of this character, the retention of the genus Echinorhynchotaenia 
 seems justified at the present time. Although the structure of the proboscis 
 has not been studied, it is probably not much different from an introvert. 
 The main difference between the introvert and the rostellum retracted as 
 a solid body is in the degree of muscular development and arrangement, 
 and serves as an important specific character but is not of generic value. 
 The arrangement of the hooks is, likewise, of less importance than the 
 internal structures of the proglottids. 
 
 ECHINORHYNCOTAENIA TRITESTICULATA FUHRMANN 1909 
 
 See Fuhrmann 1909:32-35, (Figs. 28-31) 
 Host: Anhinga rufa (Lacep. Dand) 
 Locality: Africa 
 
 Length 30 cm, width 4 to 5 mm. Testes variable in position and 3 in 
 number. Genital pores unilateral. Genital ducts pass between the longi- 
 tudinal excretory vessels. Ovary divided into two portions, each deeply 
 lobed. Uterus sac-like and lobed. 
 
 ECHINORHYNCHOTAENIA NANA MAPLESTONE 
 AND SOUTHWELL 1922 
 
 See Maplestone and Southwell 1922:193-197, (Figs. 5-7) 
 Host: Chenopsis atrata, Lath., the black swan. 
 Locality: Townsville, North Queensland. 
 
 Length 2 cm, width 1.7 mm. Scolex 1.5 mm wide and 2.3 mm long. 
 Behind each sucker is a lappet. Segments broader than long. Genital 
 pores unilateral, and open on the right hand side of the proglottid. Longi- 
 
85] STUDIES ON AVIAN SPECIES OF HYMEN0LEPID1DAE—MAYEEW 85 
 
 tudinal muscles in two layers. Unfortunately the proboscis had apparently 
 been torn out, but the "appearance of the head, with a few ragged fibers 
 protruding from the central pit, leaves no room for doubt that a proboscis 
 has been present." The material was in a bad state of preservation and 
 could not be completely described in other respects. The relation of the 
 genital ducts to the excretory vessels was not stated. This species should 
 be more completely studied from material in a better state of preservation 
 with the view of determining more accurately its relationships. 
 
 GENUS HYMENOFIMBRIA SKRJABIN 1914 
 
 Generic diagnosis: Three testis in a proglottid. Scolex with a single 
 crown of hooks. Genital pores unilateral. Excretory system consisting of 
 ten longitudinal vessels. Uterus a simple sac. Longitudinal musculature 
 consists of a single layer. Strobila well marked off into proglottids. Pseudo- 
 scolex absent. 
 
 Type species: Hymeno fimbria merganseri Skrjabin 1914. 
 
 HYMENOFIMBRIA MERGANSERI SKRJABIN 1914 
 
 See Skrjabin 1914:473-476. 
 Host: Mcrgus merganser 
 Locality: Russian Turkestan 
 
 The exact length of the parasites could not be given since the type 
 material consisted of fragments, but they were estimated as being about 
 120 to 150 mm. The maximum width has 4 mm. The scolex is 0.14 mm 
 long by 0.17 mm wide. The rostellum is armed with 10 hooks which are 
 18ju long and are shaped like Haploparaxis fihim. The neck is 0.148 mm 
 wide and 0.3 mm long. 
 
 The musculature consists of a transverse layer and a single row of 
 longitudinal bundles. The longitudinal bundles measure 34 to 41/x, and each 
 consists of from 40 to 50 fibers. There is also a diagonal muscular layer 
 outside of the longitudinal. The excretory system consists of ten parallel 
 longitudinal vessels. The lateral vessels are asymmetrically placed, two 
 lying outside the longitudinal nerve on one side while on the opposite they 
 are median to the nerve. The three testes lie in a transverse row, one being 
 poral and the other two antiporal to the female reproductive glands. The 
 female reproductive glands are median, and are relatively small. The 
 ovary is somewhat indented on the anterior margin, while the vitelline 
 gland is median and directly behind the ovary. The uterus is sac-like and 
 extends the entire width of the proglottid. 
 
 GENUS FIMBRIARIA FROELICH 1802 
 
 Scolex small and usually lost, with rostellum armed with a single row 
 of hooks. Strobila without true segments, but with transverse grooves 
 
86 ILLINOIS BIOLOGICAL MONOGRAPHS [86 
 
 giving the appearance of segments. Pseudoscolex retains the true seg- 
 mentation. Excretory system consists of several pairs (three and eleven 
 in the two known species) of longitudinal excretory vessels. Genital 
 pores marginal, unilateral, and on the right hand border of the strobila. 
 Testes three in number for each cirrus pouch. Ovary, reticular or forming 
 network extending through the strobila, or a single simple ovary for each 
 set of reproductive organs. Uterus reticular for the species known. 
 Type species Fimbriaria fasciolaris (Pallas 1781). 
 
 FIMBRIARIA FASCIOLARIS (PALLAS) 1781 
 
 Synonyms, Taenia fasciolaris Pallas 1781; T. malleus Goeze 1882; Fimbriaria malleus 
 Frohlich 1802; Fimbriaria mitra Frolich 1802; Alysclminthus malleus (Goeze 1782) Zeder 1800; 
 Halysis malleus (Goeze 1782) Zeder 1803; T. trilineata Batsch 1786; Taenia pediformis Krefft 
 1871 ; Epision plicatus Linton 1892; Fimbriaria plana von Linstow 1905; Notobolhrium arcticum 
 von Linstow 1905. 
 
 ' This species has been very much misunderstood and hence has resulted 
 the long list of synonyms recorded above. Its anatomy is very well de- 
 scribed by Wolffhugel 1900, but the true nature of the pseudoscolex, and 
 the arrangement of the reproductive organs were not fully described. 
 These points have been very clearly elucidated by Fuhrmann, 1914, who 
 arrived at the conclusion that the pseudoscolex, instead of being an ab- 
 normal portion of the strobila is the most normal, and that there were 
 three testes for each cirrus sac which are arranged in a linear series. For 
 a description of this species, the reader should refer to Wolffhugel 1900, 
 and to Fuhrmann 1914. 
 
 FIMBRIARIA INTERMEDIA FUHRMANN 1914 
 
 This species is well described by Fuhrmann (1914: 446) and was 
 obtained from the digestive tract of Somateria mollis sima. For a detailed 
 description the reader is referred to his account. 
 
87] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 87 
 
 SUBFAMILY DIORCHINAE 
 
 Subfamily diagnosis: Hymenolepididae with regularly two testes in 
 each proglottid. 
 
 Type genus: Diorchis Clerc 1903. 
 
 GENUS DIORCHIS CLERC 1903 
 
 Two testes in a proglottid. Rostellum armed with a single crown of ten 
 hooks in all the described species. Suckers unarmed or armed with minute 
 spines. Inner longitudinal muscle layer consisting of eight bundles, four 
 dorsal and four ventral. Genital pores unilateral. Uterus sac-like. In birds. 
 
 Type species: Diorchis acuminata (Clerc 1902) Clerc 1903. 
 
 DIORCHIS ACUMINATA (CLERC) 1902 
 
 See Clerc 1903:281-284, (Figs. 25, 78, 88); Ransom 1909:42-48, (Figs. 30-36). 
 Hosts: Netlion crecca, Mareca pendope, Chaulelasmus streperus, Fulica atra, Fulica 
 americana. 
 
 Locality: Europe and North America. 
 
 This species is well described by Ransom and Clerc, and the following 
 description is based upon the details given in their accounts. The hooks 
 are ten in number and 38/x in length. The length is 35 mm and the width 
 0.65 mm. The full-grown worm is probably somewhat longer, as the final 
 segments were not gravid in Ransom's material. The longitudinal muscles 
 are typical of the genus and consist of two layers, the outer composed of 
 numerous small, and the inner of eight large bundles. The excretory vessels 
 lie so that the dorsal is directly above the ventral, and are not connected 
 by transverse vessels. The cirrus sac and vagina pass dorsal to the ex- 
 cretory vessels and nerve. The two testes are located near the dorsal 
 surface in the posterior portion of the segment, one on either side of the 
 median line, and reach a maximum size of 100 to 130yti. An internal and an 
 external seminal vesicle is present. Cirrus sac is elongated, extending 
 transversely across the proglottid, its inner end not reaching the median 
 line. The cirrus is unarmed and has a globular swelling at its base. The 
 vagina forms a seminal vesicle median to the excretory ducts and reaches 
 the inner end of the cirrus sac. The ovary is trilobed, one lobe being anterior 
 and median and the others lateral, often by a division of the left lateral 
 it becomes four-lobed. When fully developed, it extends laterally as far 
 as the excretory canals and the median lobe extends forward to the anterior 
 border of the segment. The yolk gland is spherical, 45 to 60/U in diameter, 
 
88 ILLINOIS BIOLOGICAL MONOGRAPHS [88 
 
 located in the median line and behind the middle of the ovary. The uterus 
 is sac-like, developing large lobes which penetrate between the longitudinal 
 muscles and beyond the longitudinal excretory vessels. The eggs are 
 elongate. Jacobi (1898) described the anatomy of Taenia inflata Rudolphi, 
 a species very similar to D. acuminata , but Ransom thinks this should 
 be regarded as a separate form. 
 
 DIORCHIS AMERICANA RANSOM 1909 
 
 See Ransom 1909:48-51 
 Host : Fulica americana 
 Locality: Nebraska, United States. 
 
 The length of specimens of this specimens in which eggs were not yet 
 fully mature was 20 to 25 mm and the maximum width 0.6 mm. Rostellum 
 armed with ten hooks 65p long. Suckers covered with minute spines. The 
 genital pores are unilateral on the right-hand margin of the strobila at 
 about the middle of the proglottid. Nervous system and musculature 
 similar to those in D. acuminata. Vagina and cirrus pouch dorsal to the 
 nerve and excretory vessels. 
 
 The testes, two in number, of a maximum size of 100 to 130ju, are 
 located in the posterior portion of the segment, dorsal and one on either 
 side of the median line. The cirrus sac extends beyond the median line. 
 Internal and external seminal vesicles are present. The cirrus is very 
 slender and without bulbous enlargement at the base. 
 
 The vagina forms an elongated seminal receptacle median to the 
 excretory ducts which extends as far medially as the cirrus sac. The ovary 
 is trilobed with occasionally a fourth lobe on the left hand side. Yolk gland 
 similar in shape and location to these organs in D. acuminata. The uterus 
 is a simple sac, and, when fully developed, extends from the posterior to 
 the anterior border of the segment and laterally beyond and dorsal to the 
 excretory canals on the right and ventral to the excretory canals on the 
 left side of the proglottids. Eggs containing fully developed oncospheres 
 were not present in the type material. 
 
 DIORCHIS FLAVESCENS (KREFFT) 1871 
 
 SeeKrefft 1871:15 and Johnston 1912:15 
 
 Hosts: Anas superciliosa, Spatula rkynchotis, Nctlion caslaneum and Aythya australis. 
 
 Locality: Australia. 
 
 This species was originally described by Krefft under the name of 
 Taenia flavescens. His description was very insufficient, but fortunately, 
 the type material was reexamined and a very satisfactory description given 
 by Johnston (1912). 
 
 The specimens were from 3 to 5 cm in length in most cases but some 
 were as long as 8.4 cm. The suckers are armed with minute spines. Ros- 
 
89] STUDIES ON AVIAN SPECIES OF BYMEN0LEP1DIDAE—MAYHEW 89 
 
 tellum armed with ten hooks 68/1 long, arranged in a single circle. Longi- 
 tudinal musculature arranged in two series, an outer of numerous small 
 and an inner of eight large bundles. Genital ducts pass dorsal to the 
 excretory vessels. Genital pores are unilateral on the right hand side of 
 proglottid. The two testes are medially placed and attain a size of 0.1 mm. 
 Cirrus sac reaches the middle line and sometimes much farther. An 
 internal and an external seminal vesicle present. Ovary compact, trilobed, 
 and medially placed on the ventral side of the proglottid. When mature 
 the ovary reaches from the excretory vessels of one side to those of the 
 other, one lobe being median and anterior while the others are lateral. 
 The yolk gland is rounded or kidney-shaped and more dorsal in position 
 than the ovary. Vagina forms a seminal receptacle. The uterus extends 
 beyond the excretory ducts, lying dorsal to them on the poral side, but 
 ventral on the antiporal side of the proglottid. Mature eggs are from 90 to 
 107ju in length and from 27 to 31/t in width. Each end is somewhat bluntly 
 pointed, while each extremity of the inner shell is produced into a very 
 prominent process. The inner shell measures from 54 to 68/x in length by 
 about 16ju in breadth. 
 
 DIORCHIS INFLATA (RUDOLPHI) 1809 
 
 See Krabbe 1869:285-286, (Figs. 109-11) (Taenia inflata). Jacobi 1898:95-104, (pi. 6, 
 16 fig.) (J. inflata); Cohn 1901 :330-331, Hymenolepis inflata; Clerc 1903: 284-288, (Fig. 89); 
 von Linstow 1906:15-17, (Figs. 17-18), (H. inflata) 
 
 Host: Fulica atra (L.) 
 
 Locality: Europe. 
 
 The length of this cestode is 80 to 100 mm and its width is 2 to 3 mm. 
 The ten hooks are 23/x long, according to Jacobi. The testes are large and 
 centrally located in the proglottid, the two reaching to the excretory 
 vessels on either side. The ovary and vitelline gland are centrally located. 
 The cirrus sac does not reach the center of the proglottid. The above data 
 are from Jacobi, and since the species has not been reported in the western 
 hemisphere, further details are not included in this report. 
 
 DIORCHIS PARVICEPS (VON LINSTOW) 1872 
 
 See von Linstow 1872-57 (Figs. 11-12); 1904:306-307 (Figs. 23-25) 
 Host: Mergus senator. 
 Locality: Europe. 
 
 The length of the specimens of this species is recorded as being 110 mm, 
 and 2.16 mm in maximum width. The pores are unilateral and marginal. 
 The rostellum has ten small hooks 12^ long. The two testes are oval, 130 
 by 79/x in size. Ovary consists of a number of parts arranged rosette-like 
 in the center of the proglottid. The vitelline gland is located in the center 
 of the ovarian group. 
 
90 ILLINOIS BIOLOGICAL MONOGRAPHS [90 
 
 DIORCHIS EXCENTRICUS N. SP. 
 
 A number of specimens of a small species of Diorchis were taken from 
 the posterior half of the intestine of Erismaliira jamaicensis, the ruddy 
 duck, killed at Peoria, Illinois, November 23, 1923. They are preserved 
 in the author's collection under the number 576b. 
 
 The length of these worms varies from 26 mm to 52 mm. Even the 
 longest specimen contained no mature eggs, and the uterus was not yet 
 developed in any of the posterior proglottids. The width of proglottids 
 about 30 mm behind the scolex is about 0.7 mm and in the longest a 
 maximum width of 1.4 mm near the posterior end of the strobila. Im- 
 mediately behind the scolex, the proglottids are about 190^t wide. The 
 pores are unilateral and on the right hand side of the proglottid. 
 
 The scolex is relatively inconspicuous. It is scarcely wider than the 
 strobila immediately behind, but the suckers extend outward on each side, 
 marking off this region from that immediately behind. Its length and width 
 are about equal, about 175/1. The rostellum is about 75p long when ex- 
 tended, and has a slightly enlarged distal portion about 70^ in diameter. 
 It carries a crown of ten hooks, each of which is shaped as shown in figure 
 107. In length they measure 26jx to 31/i. When retracted the blades of the 
 hooks are directed backward, showing that it is retracted as a solid muscular 
 organ. 
 
 In the male reproductive system the two testes are large organs occupy- 
 ing the larger part of the interior of the proglottid. They are transversely 
 placed in the posterior portion of the proglottid and somewhat toward the 
 poral side, the ovary being slightly in the antiporal portion. The poral testis 
 is regularly found almost directly dorsal to the longitudinal excretory 
 ducts on that side. The nerve is found ventral to that portion of the testis, 
 The antiporal testis reaches the excretory vessels of the antiporal side. 
 There are two testes in each proglottid in each case observed and their 
 position is very constant. 
 
 The cirrus sac is elongated and of about the same diameter throughout 
 its entire length, and reaches somewhat beyond the excretory vessels on 
 the poral side. A rounded external seminal vesicle is located at the inner 
 end of the cirrus sac. The cirrus is large and thickly set with conspicuous 
 spines. The internal seminal vesicle occupies the larger part of the cirrus 
 sac. The genital ducts lie dorsal to the longitudinal excretory vessels and 
 the pore is on the right hand side of the proglottid. 
 
 In the female reproductive system the first trace of the ovary is located 
 on the ventral side and near the antiporal excretory vessels. As sexual 
 development proceeds, the ovary grows laterally beneath the excretory 
 ducts, and medially, reaching, when fully developed, to the poral excretory 
 ducts or slightly beyond. When extending beyond the excretory vessels 
 on the poral side, it lies dorsal to them, which is due to the ventral dis- 
 
91] STUDIES ON AVIAN SPECIES OF BYMENOLEPIDIDAE—MAYHEW 91 
 
 placement of the ducts by the cirrus sac and testis. The ovary at no time 
 is conspicuously lobed, but in its earlier stages has a few shallow con- 
 strictions along its margin. The vitelline gland is a rounded, cval, or egg- 
 shaped organ lying directly posterior to the ovary. The vagina is a thin- 
 walled duct leading directly from the region of the vitelline gland to the 
 pore. It is sometimes distended throughout almost its full length by 
 spermatozoa, but usually only its inner end functions as a seminal re- 
 ceptacle. 
 
 The two layers of longitudinal muscles are well differentiated. The 
 inner one is composed of eight large bundles, four ventral and four dorsal 
 and placed as indicated in figure 106. The outer contains numerous much 
 smaller bundles arranged in an almost symmetrical row in the outer 
 portion of the proglottid. 
 
 Of the species of Diorchis which have been previously described, there 
 are none which show much similarity either in shape of hooks or the 
 arrangement of the internal organs. The two species which have been 
 described from America have the testes median in position and hooks with 
 a much longer blade in proportion to the base. The hooks of D. americana 
 are about twice as long as in the above described species. In D. acuminata, 
 whose hooks are about the same in length as those described above, the 
 ovary is median, deeply lobed, and smaller, while in our species it is 
 antiporal, transversely elongated, and scarcely lobed. 
 
92 ILLINOIS BIOLOGICAL MONOGRAPHS [92 
 
 SUBFAMILY HAPLOPARAXINAE 
 
 Subfamily diagnosis: Hymenolepididae with regularly a single testis 
 in each proglottid. 
 
 Type genus: Haploparaxis Clerc 1903. 
 
 GENUS HAPLOPARAXIS CLERC 1903 
 
 Number of testes, one. Scolex with rostellum armed with a single row 
 of 10 to 46 hooks in the species described. Genital pores unilateral. Genital 
 ducts pass above the excretory vessels in all the species so far mentioned 
 except H. furcigera (Rud. 1819) Fuhrmann 1908, which has the genital 
 ducts passing between the excretory vessels and ventral to the nerve, 
 according to von Linstow (1905, figure 8, p. 23). Uterus a simple sac. 
 In birds. 
 
 Type species: Haploparaxis filiim (Goeze 1782) Clerc 1903. 
 
 LIST OF SPECIES 
 
 Haploparaxis australis Johnston 1911. See Johnston 1911:90 
 
 Host : Gallinago australis 
 
 Locality: Australia 
 
 Hooks: 8, 19 to 22m in length 
 
 Eggs: 57 by 42m; oncosphere 34 by 25m 
 Haploparaxis brachyphallos (Krabbe 1869) 
 
 See Krabbe 1869:310-311 {Taenia brachyphallos) 
 
 Syn: Hymenolepis brachyphallos (Krabbe) Fuhrmann 1906 
 Skorikowia claiisa von Linstow 1905 
 Diorchis serpentata von Linstow 1905 
 
 Hooks: 10, 17 to 18m in length 
 Haploparaxis cirrosa (Krabbe 1869) Clerc 1903 
 
 See Krabbe 1869:308 (Taenia cirrosa); Clerc 1903:269-271. 
 
 Hooks: 10, 24m in length 
 Haploparaxis crassirostris (Krabbe 1869) Clerc 1903. 
 
 See Krabbe 1869:314 (Taenia crassirostris); Clerc 1903:265-267. 
 Haploparaxis diminuens von Linstow 1905. 
 
 See von Linstow 1905b :8-9. 
 
 Hooks: 10, 14.3m in length. 
 Haploparaxis dujardinii (Krabbe 1869) Clerc 1903. 
 
 See Krabbe 1869:319-320 (Taenia dujardinii); Fuhrmann 1895:436 (Taenia dujardinii); 
 Clerc 1903:274-275. 
 
 Hooks: 46, 16 to 18m in length. 
 Haploparaxis elisae Skrjabin 1914. 
 
 See Skrjabin 1914:451. 
 
 Hooks 10, 25.9m in length. 
 
93] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 93 
 
 Haploparaxis filium (Goeze 1782) Clerc 1903. 
 
 See Krabbe 1869:312-313 {Taenia filum); Clerc 1903:257-263. 
 
 Hooks: 10, 17 M to 18.5m. 
 Haploparaxis furcigera (Rud. 1819) Fuhrmann 1908. 
 
 See Krabbe 1869:315 (Taenia rhomboidea); 
 Stiles 1896:34-35 (Dicranotaenia furcigera). 
 
 Hooks: 10, 47m to 58m in length. 
 Haploparaxis Ursula (Krabbe 1882) Clerc 1902, 1903. 
 
 See Krabbe 1882:9 (Taenia pubescens); Clerc 1903:267-269. 
 
 Syn: Taenia pubescens Krabbe 1882, Monorchis hirsuta Clerc 1902. 
 
 Hooks: 10, 37m to 39m in length. 
 Haploparaxis larina Fuhrmann 1901. 
 
 See Fuhrmann 1901-03:518-520. 
 
 Hooks: 10, 21.6m to 23m in length. 
 Haploparaxis murmanica Baylis 1919. 
 
 See Baylis 1903:512-513. 
 
 Hooks: 10, 65m in length. 
 Haploparaxis penetrans (Clerc 1902). 
 
 See Clerc 1903:271-274. 
 
 Hooks: 10, 40m long. 
 Haploparaxis sphaerophora (Rud. 1810) Fuhrmann 1906. 
 
 See Fuhrmann 1906e:739. 
 Hapoplaraxis fuligidosa Solovvicw 1911. 
 
 SPECIES INQUIRENDAE 
 
 Hymenolepis bitharzii Krabbe 1869. See Krabbe 1869:73 
 
 Hymenolepis brcvkirrosa Fuhrmann 1918. See Fuhrmann 1918:402 
 
 Hymenolepis cantaniana (Polonio 1860) Ransom 1909. See Ransom 1909:36-41 
 
 Hymenolepis dahurica von Linstow 1903. See von Linstow 1903: 290. 
 
 Hymenolepis exilis (Dujardin 1845) Fuhrmann 1906. See Stiles 1896:58 
 
 Hymenolepis fusa Krabbe 1869. See Krabbe 1869:307 
 
 Hymenolepis fringillarum (Rudolphi 1809). See Krabbe 1869:326 
 
 Hymenolepis filirostris (Wedl. 1856). See Wedl. 1856:15 
 
 Hymenolepis fallax (Krabbe 1869). See Krabbe 1869:71 
 
 Hymenolepis groenlandica (Krabbe 1869). See Krabbe 1869:68 
 
 Hymenolepis liophallos (Krabbe 1869). See Krabbe 1869:43 
 
 Hymenolepis minor (Krabbe 1869) (T. minula). See Krabbe 1869:292 
 
 Hymenolepis macracanthos von Linstow 1877. See Linstow 1877:16 
 
 Hymenolepis micrancri strata Wedl 1856. See Wedl 1856:6 
 
 Hymenolepis naja (Dujardin 1845). See von Linstow 1872:57. 
 
 Hymenolepis orientalis (Krabbe 1879) Fuhrmann 1906. See Krabbe 1879:11, 1882:360 
 
 Hymenolepis pelrocinclae (Krabbe 1882). See Krabbe 1882:356 
 
 Hymenolepis parvirostellata von Linstow 1901. See von Linstow 1901:426. 
 
 Hymenolepis polygramma (von Linstow 1875). See von Linstow 1875:186. 
 
 Hymenolepis paadifera (von Linstow 1879). See von Linstow 1879:186. 
 
 Hymenolepis pigmentata (von Linstow 1872). Fuhrmann 1906. See von Linstow 1872:56. 
 
 Hymenolepis recurvirostrae (Krabbe 1869). See Krabbe 1869:60 
 
 Hymenolepis rosseteri Blanchard 1891. See Blanchard 1891 :424-428 
 
 Hymenolepis siberica von Linstow 1905. See von Linstow 1905:6-7. 
 
 Hymenolepis spherophora (Rudolphi 1810) Fuhrmann 1906 
 
 Hymenolepis sagiita Rossetter. 1906. See Rossetter 1906:275 
 
94 ILLINOIS BIOLOGICAL MONOGRAPHS [94 
 
 Hymenolepis trichorhynchus Yoshida 1910. See Yoshida 1910:241 
 Hymenolepis trichodroma Fuhrmann 1908. See Fuhrmann 1908:80 
 Hymenolepis tenerrima (von Linstow 1882). See von Linstow 1882:21. 
 Hymenolepis fuliginosa (Krabbe 1882). See Krabbe 1882:355 
 Hymenolepis vallei (Stossich 1892) Fuhrmann 1906. See Stossich 1892:68-69. 
 Hymenolepis megalorhyncha (Krabbe 1869). See Cohn 1901:270 
 Hymenolepis (Drepanidotaenia) podicipina Szymanski 1905. 
 
 See Szymanski 1904:342-344, (Fig. 1-5); 1905:733-734, (Fig. 1-5). The position of 
 the testes in this species is described as follows: "Die drei rundlichen Hoden liegen so 
 dass der eine nahe dem inneren Ende des Cirrusbeutels, die beiden anderen, der eine 
 iiber dem anderen, an der entgegengesetzten Seite liegen (Fig. 3, 5, tes.)." This species 
 should be restudied and the constancy of this position determined. It is probable that 
 this characteristic position, if constant, may serve to distinguish this form as another 
 genus distinct from those defined above. 
 Echinocolyle uralensis Clerc 1902. 
 
 See Clerc 1903 :315-317, (Fig. 28, 32, 34, 37, and 89) . The position of the testes of this 
 species is described as follows (p. 316): "Les trois testicules sont dorsaux et disposes 
 d'une maniere particuliere; les deux testicules marginaux (PI. 9, fig. 34; PL 10, fig. 38) 
 se trouvent plus en avant que le troisieme qui est median. Cette position est deja bien 
 accuse e dans les proglottis ayant des organes femelles a peine Sbauches; elle s'accentue 
 encore quand la vesicule seminale et le receptacle seminal sont gonfles." The description 
 and figures indicate that this is a very characteristic pattern of testes arrangement, but 
 the material should be re-examined before a separate genus is denned. 
 
 The following species are closely related to E. uralensis in the arrangement of the 
 testes. 
 
 Hymenolepis clausa von Linstow 1906. 
 
 See von Linstow 1906a:177-178 (Figs. 22-23) 
 Hymenolepis terraereginae Johnston 1911. 
 
 See Johnston 1911-89 (Figs. 25-26) 
 Hymenolepis fasciata (Rudolphi 1810). 
 
 See Krabbe 1869:300 (Figs. 156, 157) (Taenia fasciata); Stiles 1896:37-38, 
 (Figs. 56-79) (Drepanidotaenia fasciata; Cohn 1901:320; Clerc 1903:307 
 (Drepanidotaenia fasciata) 
 
95] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 95 
 
 XII. SUMMARY 
 
 1. A revision of the genus Hymenolepis is made on the basis of the 
 arrangement of the testes, and a division of the species assigned to 
 it into three genera. 
 
 2. The patterns of testes arrangement serve as reliable generic char- 
 acters because: 
 
 (a) they are invariably in the same relative positions with reference 
 to each other in all of the proglottids of the strobila of species 
 having a constant arrangement, and 
 
 (b) the compound nature of the testes indicates that cestodes 
 having the same pattern of arrangement are closely related 
 since it is believed that in the phylogeny of the group several 
 (two to four) testes became definitely localized in the pro- 
 glottid and afterwards united, resulting in the compound testes 
 with the different patterns of arrangements found in the present 
 species. The evidence for the compound nature of the testes 
 is presented under the following topics: 
 
 (1) the irregularities in the number and branching of the 
 vasa efferentia in five species; 
 
 (2) the lobing of the testes; 
 
 (3) the irregularities in the number and position of the 
 testes in one species. 
 
 3. Fourteen new species belonging to the family are described. 
 
96 ILLINOIS BIOLOGICAL MONOGRAPHS [96 
 
 NEW GENERA DESCRIBED IN THIS PAPER 
 
 Wardium 76 
 
 Weinlandia 52 
 
 NEW SPECIES DESCRIBED IN THIS PAPER 
 
 Oligarchis longivaginosus 34 
 
 Wardium fryei 80 
 
 variabiie 77 
 
 Hymenolepis lobulata 43 
 
 cuncala 45 
 
 sacciperium 48 
 
 Weinlandia macrosirobilodes 65 
 
 cyrtoides 59 
 
 lateralis 56 
 
 corvi 62 
 
 planestici 73 
 
 introversa 67 
 
 microcirrosa 70 
 
 Diorckis excentricus 87 
 
97] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 97 
 
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 Micr. Club, 10:31-40; pis. 5-6. 
 
 1908. Hymenolepis farciminalis. Jour. Quekett Micr. Club, 10:295-310; pi. 24. 
 
 1908. On Hymenolepis fragilis. Jour. Quekett Micr. Club, 10:229-234; pi. 18. 
 
 1909. Hymenolepis acicula sinuata, a new species of Tapeworm. Jour. Quekett Micr. 
 Club, 10:393-402; pi. 30. 
 
 1911. Hymenolepis upsilon: a new species of avain tapeworm. Jour. Quekett Micr. 
 Club, 11:147-160; pi. 6. 
 Rudolphi, Carl A. 
 
 1808-10. Entozoorum sive vermium intestinalium historia naturalis. Amstelaedami. 
 2 vols. 
 Schmidt, J. E. 
 
 1899. Die Entwichlungsgeschichte und der anatomische Bau der Taenia anatina(Kiab- 
 be). Arch. Naturg., 60. J., 1:65-113. 
 Shipley, A. E. 
 
 1897. On Drepanidotaenia hemignathi, a New Species of Tapeworm. Quart. Jour. Micr. 
 
 Sci., 40:613-621; pi. 46. 
 [1908.] Interim report on the parasites of grouse. 12 pp. fol. London. 
 
 1909. The tapeworms (Cestoda) of the red grouse {Lagopus scoticus). Proc. Zool. Soc. 
 London, 1909:351-363; pis. 56-60. 
 
 1910. Grouse Disease. London. 15 pages. Reprinted from the Times of Apr. 19 and 
 25, 1910. 
 
 Skejabin, R. J. 
 
 1914. Vogel cestoden aus Russisch Turkestan mit 12 Tafeln und 4 Abbildungen im 
 
 Text. Zool. Jahrb., Syst., 37:411-492; pis. 16-27. 
 1914a. Zwei Yogelcestoden mit gleicher Scole.x-bewaffung und verschiedener Organisa- 
 tion. (Hymenolepis collaria Batsch und Hymenolepis compressa Linton). Cen- 
 tralbl. Bakt., Abt. I, 74:275-278; 7 figs. 
 Southwell, T. 
 
 1914. A Short Account of Our Present Knowledge of the Cestode Feuna of British India 
 
 and Ceylon. Jour. Proc. Asiatic Soc. Bengal, 10:139-145. 
 1916. On Some Indian Cestoda, Part II. Records Indian Museum, 12:5-20. 
 
 1921. Cestodes from Indian Poultry. Ann. Trop. Med. Par., 15:161-166. 
 
 1922. Cestodes from Indian birds with a note on Ligula inlestinalis. Ann. Trop. Med. 
 Par., 16:355-382; 14 figs. 
 
 Stiles, C. W. 
 
 1896. Report upon the present knowledge of the tapeworms of poultry. Bur. An. Ind. 
 Bull. 12, 79 pp., 21 pis. 
 
 1903. The Type species of the cestode genus Hymenolepis. Bull. Hyg. Lab., 13:19-21. 
 
 1906. Illustrated key to the cestode parasites of man. Bull. Hyg. Lab., 25:1-104, 
 166 figs. 
 Stossich, M. 
 
 1893. Note Elmintologiche. Boll. soc. Adriatica sci. nat. Trieste, 14:83-89; figs. 1-7. 
 
 1896. Ricerche Elmintologiche. Boll. Soc. adriat. sci. nat. Trieste, 17:121-136; pis. 3-4. 
 Sweet, Geoegina 
 
 1909. The Endoparasites of Australian Stock and Native Fauna. Proc. Roy. Soc. 
 Victoria, 21:454-502; pi. 29. 
 
 1910. Some New and Unrecorded Endoparasites from Australian Chickens. Proc. 
 Roy. Soc. Victoria, 23:242-256; pis. 31-35. 
 
103] STUDIES ON A VIAN SPECIES OF HYMENOLEPIDIDAE—MA YHEW 103 
 
 SZYMANSKI, M. 
 
 1904. Przycynck de helmintologie. Rosp. . . . wydz. mathemat.-przyr. Akad. Umiej. 
 w. Krakow. 44: (3rd ser., V. 4, pt. B.) 342-345; pi. 8. 
 
 1905. (Abstract of 1904) Bull. Int. Acad. sci. Cracovie, cl. sc. Math, et nat., no. 10, 
 pp. 733-735; pi. 16. 
 
 Volz, W. 
 
 1900. Beitrag zur Kenntnis einiger Vogelcestoden. Arch. Naturg., J. 66, 1:115-174; 
 4 figs., pis. 6-8. 
 
 Ward, H. B. 
 
 1901. Internal Parasites of Nebraska Birds. Proc. Nebr. Ornithol. Union, 2:63-70; 
 pi. 6-7. 
 
 1918. Parasitic Flatworms. In Ward & Whipple, Fresh-water Biology, pp. 365-453; 
 114 figs. John Wiley & Sons, New York. 
 Wedl, Carl 
 
 1856. Characteristik mehrerer grosstenteils neuer Taenien. Sitzungsb. Akad. Wiss. 
 Vienna, math.-nat. Class., 18:5-27, pis. 1-3. 
 Weinland, D. F. 
 
 1856. Observations on a new genus of taenoids. Proc. Bost. Soc. Nat. Hist., 6:59-63, 
 
 discussion pp. 62-63. 
 1858. Human Cestodes. An Essay on the Tapeworms of Man. Cambridge, 93 pp.: 
 
 12 figs. 
 1861. Beschreibung zweier neuer Taenioiden aus dem Menschen. Nova acta Acad. nat. 
 curios., 28:1-24, pis. 1-5. 
 WolffhOcel, K. 
 
 1899. Rechtfertigung gegenuber Cohn's Publikation "Zur Systematik der Vogeltanien" 
 II. Centralbl. Bakt., 1. Abt., 26:632-635. 
 
 1899a. Beitrag zur Kenntnis der Anatomie einiger Vogelcestoden. Zool. Anz., 22:217-223. 
 
 1900. Beitrag zur Kenntnis der Vogelhelminthen. Diss. Basel, 204 pp., 7 pis. 
 
 1900a. Drepanidotaenia lanceolala Bloch. Centralbl. Bakt., Abt. 1, 28:49-56; figs. 1-6. 
 Yoshida, S. 
 
 1910. On Three New Species of Hymenolepis found in Japan. Annot. Zool. Jap., 7: 
 235-246; 25 figs. 
 
 ZSCHOKKE, F. 
 
 1888. Rocherches sur la structure anatomique et histologique des cestodes. 396 pp., 
 
 9 pis. Geneve. 
 1888a. Ein Beitrag zur Kenntniss der Vogeltanien. Centralbl. Bakt., 3:41-46. 
 
104 ILLINOIS BIOLOGICAL MONOGRAPHS [104 
 
 EXPLANATION OF PLATES 
 
 AH of the drawings were made with the aid of a camera lucida, and the details filled in at 
 the same magnifications. In drawings of cross sections the excretory vessels have been indi- 
 cated by heavy lines and the nerve cord filled in solid. 
 
 ABBREVIATIONS USED 
 
 c 
 
 cirrus 
 
 cs 
 
 cirrus sac 
 
 St 
 
 seminal receptacle 
 
 SV 
 
 external seminal vesicle 
 
 t 
 
 testis 
 
 ut 
 
 uterus 
 
 vag 
 
 vagina 
 
105] STUDIES ON A VI AN SPECIES OF HYMENOLEPIDIDAE—MA YHEW 105 
 
 PLATE I 
 
106 ILLINOIS BIOLOGICAL MONOGRAPHS [106 
 
 PLATE 1 
 
 1. XV einlandia microcirrosa. Vasa efferentia from four consecutive proglottids. X48 
 
 2. XV einlandia macrostrobilodes, vasa efferentia from seven consecutive proglottids. X 150 
 
 3. W einlandia macrostrobilodes, vasa efferentia from consecutive proglottids of another 
 specimen than those in figure 2. X 123 
 
 4. XV einlandia corvi, vasa efferentia from three proglottids in the same strobila. X333 
 
ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 VOLUME X 
 
 MAYHEW AVIAN HYMENOLEPIDIDAE PLATE I 
 
107] STUDIES ON A VI AN SPECIES OF HYMENOLEPIDWAE—MA YHEW 107 
 
 PLATE II 
 
108 ILLINOIS BIOLOGICAL MONOGRAPHS [108 
 
 PLATE 2 
 
 5. Hymenohpis sacciperium, vasa efferentia from six consecutive proglottids. X 123 
 
 6. Weinlandia planestici, five consecutive proglottids. X80 
 
 7. Hymenohpis lobulala, retracted rostellum. X80 
 
 8. Wardiitmfryci, extruded cirrus. X33 
 
 9. Hymenohpis amenta, testes and vasa efferentia. X47 
 
 10. Weinlandia planestici, three consecutive proglottids. X123 
 
 11. Weinlandia planestici, seven consecutive proglottids. X80 
 
ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 'OLUME N 
 
 MAYHEW 
 
 AVIAN HYMENOLEPIDIDAE PLATE II 
 
109] STUDIES ON A VI AN SPECIES OF HYMENOLEPIDIDAE—MA YBEW 109 
 
 PLATE III 
 
110 ILLINOIS BIOLOGICAL MONOGRAPHS [110 
 
 PLATE 3 
 
 12. Oligorchis longivaginosus, drawing showing location of organs in transverse section. X 160 
 
 13. Oligorchis longivaginosus , scolex with incomplete set of hooks. X50 
 
 14. Oligorchis longivaginosus, three consecutive proglottids showing variations in teste ; 
 arrangement. 
 
 15. Oligorchis longivaginosus, frontal view of organs from toto mount. X80 
 
 16. Oligorchis longivaginosus, hook. X355 
 
 17. Wardium variabile, transverse section. X125 
 
 18. Wardium variabile, scolex. X160 
 
 19. Wardium variabile, hook. X600 
 
 20. Wardium variabile, uterus from frontal section. X80 
 
 21. Wardium variabile, cirrus sac from frontal section. X270 
 
 22. Wardium variabile, showing position of organs in frontal section. X80 
 
 23. Wardium variabile, excretory system in frontal section. X125 
 
ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 VOLUME N 
 
 MAYHEW AVIAN HYMEXOLEPIDIDAE PLATE III 
 
Ill] STUDIES ON A VI AN SPECIES OF HYMENOLEPIDIDAE—MA YEEW 111 
 
 PLATE IV 
 
112 
 
 ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 [112 
 
 PLATE 4 
 
 24. Wardiumfryei, 
 
 25. Wardiumfryei, 
 
 26. Wardium fryei, 
 
 27. Wardiumfryei, 
 
 28. Wardium fryei, 
 
 29. Wardiumfryei, 
 
 30. Wardium fryei, 
 
 "", testes arrangement in nine consecutive proglottids. X50 
 ;j, egg. X485 
 s», scolex. X 195 
 », hook. X750 
 
 ez, drawing of organs from several frontal sections, ventral view. XI 40 
 ', cirrus sac and vagina in transverse section. X140 
 "*, transverse section showing course of uterus. X25 
 
 31. Wardium fryei, transverse section showing testes, ovary, and vitelline gland. XI 40 
 
 32. Hymenolepis lobulala, transverse section. X50 
 
 33. Hymenolepis lobulala, cirrus sac and vagina in transverse section. X150 
 
 34. Hymenolepis lobulata, scolex. X50 
 
 35. Hymenolepis lobulala, hook. X450 
 
 36. Hymenolepis lobulata, egg. X300 
 
 37. Hymenolepis lobulata, rostellum. X 160 
 
 38. Hymenolepis lobulata female reproductive organs from frontal section. X10 
 
 39. Hymenolepis lobulala, male organs in frontal section. X40 
 
ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 VOLUME X 
 
 MAYHEW AVIAN HYMENOLEPIDIDAE PLATE IV 
 
113] STUDIES OX A VIAX SPECIES OF HYMENOLEPIDIDAE—MA YHEW 113 
 
 PLATE V 
 
1 1 4 ILLINOIS BIOLOGIC A L MOKOGRA PBS 1114 
 
 PLATE 5 
 
 40. Hymenolepis sacciperium, from frontal sections. X40 
 
 41. Hytnenolepis sacciperium, uterus. X25 
 
 42. Hymenolepis sacciperium, egg. X350 
 
 43. Hymenolepis sacciperium, hook. X500 
 
 44. Hymenolepis sacciperium, a series of proglottid^, a-b from one strobila, c-j from another, 
 showing variations in the number and arrangement of the testes. 
 
 45. Hymenolepis sacciperium, scolex. X125 
 
 46. Hymenolepis sacciperium, transverse section showing arrangement of musculature. 
 X50 
 
 47. Hymenolepis sacciperium, reproductive organs in transverse section. X50 
 
 48. Hymenolepis cuneata, scolex. X50 
 
 49. Hymenolepis cuneata, reproductive organs in transverse section. X2S 
 
 50. Hymenolepis cuneata, vasa efferentia from one proglottid in frontal section. X155 
 
 51. Hymenolepis cuneata, hook. X350 
 
 52. Hymenolepis cuneata, cirrus sac. X80 
 
 53. Hymenolepis cuneata, from frontal sections showing position of organs. X25 
 
ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 VOLUME X 
 
 MAYHEW 
 
 AVIAN HYMENOLEPIDIDAE 
 
 PLATE V 
 
115] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 115 
 
 PLATE VI 
 
1 1 6 ILLINOIS BIOLOGIC A L MONOGRA PHS 1 11 6 
 
 PLATE 6 
 
 54. Weinlandia lateralis, a proglottid toward the anterior end of the strobila. 
 
 55. Weinlandia lateralis, hook. X730 
 
 56. Weinlandia lateralis, scolex. X115 
 
 57. Weinlandia lateralis, transverse section of a proglottid showing course of uterus. X50 
 
 58. Weinlandia lateralis, from section of proglottid farther posterior than shown in figure 
 
 54. X50 
 
 59. Weinlandia lateralis, transverse section toward the anterior end of strobila. X95 
 
 60. Weinlandia lateralis, transverse section farther posterior than figure 59. X50 
 
 61. Weinlandia lateralis, uterus in proglottid toward posterior end of strobila. X25 
 
 62. Weinlandia lateralis, vasa efferentia. X330 
 
 63. Weinlandia macrostrobilodes, section of scolex showing arrangement of muscles. X330 
 
 64. Weinlandia macrostrobilodes , uterus. X 15 
 
 65. Weinlandia macrostrobilodes, hook, X500 
 
 66. Weinlandia macrostrobilodes, egg. X330 
 
 67. Weinlandia macrostrobilodes, scolex. X 155 
 
 68. Weinlandia macrostrobilodes, proglottids from anterior end of strobila. X25 
 
 69. Weinlandia macrostrobilodes, transverse section showing course of uterus. X40. 
 
 70. Weinlandia macrostrobilodes, reproductive organs in toto. X25 
 
 71. Weinlandia macrostrobilodes, reproductive organs in toto farther anterior than figure 70. 
 X40 
 
ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 VOLUME X 
 
 MAYHEW AVIAN HYMENOLEPIDIDAE PLATE VI 
 
117] STUDIES ON AVIAN SPECIES OF UYMENOLEPIDIDAE—MAYBEW 117 
 
 PLATE VII 
 
118 ILLINOIS BIOLOGICAL MONOGRAPHS 1118 
 
 PLATE 7 
 
 72 . Weinlandia introversa, section of scolex showing arrangement of muscles. X330 
 
 73. Weinlandia introversa, scolex in toto. X160 
 
 74. Weinlandia introversa, hook. X750 
 
 75. Weinlandia introversa, proglottids from anterior portion of strobila. X25 
 
 76. Weinlandia introversa, cirrus sac. X50 
 
 77. Weinlandia introversa, reproductive organs from toto mount. X80 
 
 78. Weinlandia macrostrobilodes, transverse section. X40 
 
 79. Weinlandia corvi, reproductive organs reconstructed from frontal sections. X80 
 
 80. Weinlandia corvi, scolex. X155 
 
 81. Weinlandia corvi, reproductive organs farther posterior than figure 79. X80 
 
 82. Weinlandia corvi, hook. X550 
 
 83. Weinlandia corvi, cirrus sac and vagina. X175 
 
 84. Weinlandia corvi, transverse section. X50 
 
ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 VOLUME X 
 
 MAYHEW AVIAN HYMENOLEPIDIDAE PLATE VII 
 
119] STUDIES ON A VI AN SPECIES OF BYMENOLEPIDIDAE—MA YBEW 119 
 
 PLATE VIII 
 
120 ILLINOIS BIOLOGICAL MONOGRAPHS [120 
 
 PLATE 8 
 
 85. Weinlandia cyrtoides, cirrus sac, vagina, one testis and exretory duct in frontal section 
 X125 
 
 86. Weinlandia cyrtoides, hook. X330 
 
 87. Weinlandia cyrtoides, reproductive organs reconstructed from frontal sections. X 165 
 
 88. Weinlandia cyrtoides, cirrus sac and external seminal vesicle, frontal section. X165 
 
 89. Weinlandia cyrtoides, outline of an entire strobila showing characteristic shape. X25 
 
 90. Weinlandia cyrtoides, showing the comparative position of the cirrus sac and testes at 
 different stages of development. 
 
 91. Weinlandia microcirrosa, outline of the reproductive organs in three proglottids showing 
 variation in the position of the testes. X45 
 
 92. Weinlandia microcirrosa, outline of reproductive organs at an early stage of development. 
 X45 
 
 93. Weinlandia microcirrosa, hook. X575 
 
 94. Weinlandia microcirrosa, scolex. X330 
 
 95. Weinlandia microcirrosa, egg. X385 
 
 96. Weinlandia microcirrosa, cirrus sac. X165 
 
 97. Weinlandia microcirrosa, cross section. X54 
 
ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 VOLUME X 
 
 MAYHEW AVIAN HYMENOLEPIDIDAE PLATE VIII 
 
121] STUDIES ON A VIAN SPECIES OF HYMENOLEPIDIDAE—MA YHEW 121 
 
 PLATE IX 
 
122 ILLINOIS BIOLOGICAL MONOGRAPHS 1122 
 
 PLATE 9 
 
 98. Weinlandia planestici, proglottid showing reproductive organs. X120 
 
 99. Weinlandia planestici, egg. X485 
 
 100. Weinlandia planestici, transverse section in the region of cirrus sac. X150 
 
 101. Weinlandia planestici, hook. X700 
 
 102. Weinlandia panestici, cirrus sac. X175 
 
 103. Weinlandia planestici, scolex. X130 
 
 104. Diorchis excentricus, cirrus. X330 
 
 105. Diorchis excentricus, scolex in outline showing rostellum in a retracted condition. X190 
 
 106. Diorchis excentricus, transverse section. X80 
 
 107. Diorchis excenirkus, hook. X500 
 
 108. Diorchis excentricus, two proglottids showing male and female reproductive organs. 
 X3S 
 
 109. Diorchis excentricus , reproductive organs in two proglottids. X12 
 
 110. Diorchis excentricus, scolex. X80 
 
 111. Diorchis excentricus , male and female reproductive organs in three proglottids toward the 
 posterior end of the strobila. X80 
 
ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 VOLUME X 
 
 109 
 
 MAYHEW AVIAN HYMENOLEPIDIDAE PLATE IX 
 
123] STUDIES ON A VI AN SPECIES OF HYMENOLEPIDIDAE—MA YBEW 123 
 
 INDEX OF GENERA AND SPECIES OF THE HYMENOLEPI- 
 DIDAE DISCUSSED IN THIS PAPER 
 
 abortiva 52 
 acuminata 87 
 aequabilis 39 
 ambiguum 77 
 amphitricha 53 
 americana 88 
 anatina 40 
 annandalei 53 
 arcuata 52, 62, 64 
 ardeae 58 
 armata 55 
 
 asymetrica 14, 29, 55 
 australis 92 
 baschkiriensis 39, 59 
 biaculeata 41 
 bilharzii 72, 75 
 bilateralis 41, 59 
 bisaccata 40 
 brachycephala 41 
 brachyphallos 92 
 brasiliensis 38 
 brevis 54 
 brevicirrosa 93 
 breviannulata 38, 45 
 caprimulogorum 76 
 cantaniana 13, 73 
 capillaroides 45, 76, 77 
 capillaris 40, 45 
 capitellata 55 
 carioca 54 
 caroli 54 
 chionis 52 
 cirrosa 92 
 clausa 29 
 clandestina 40 
 collaris 52 
 columbina 54 
 compressa 39 
 corvi 54, 62 
 coronula 55, 69 
 creplini 40 
 crassirostris 92 
 cuneata 45 
 cyrtoides 59, 61 
 
 dahurica 93 
 
 delachauxi 34 
 
 diminucns 92 
 
 diminuta 38 
 
 diorchis 52, 62 
 
 Diorchis 31, 87 
 
 dujardinii 92 
 
 echinocotyle 40 
 
 Echinorhynchotaenia, 84 
 
 elisae 92 
 
 elongata 41, 58 
 
 excentricus 90 
 
 exilis 93 
 
 exigua 39 
 
 fallax 93 
 
 fasciata 94 
 
 farciminosa 52, 74 
 
 fasciolaris 86 
 
 filirostris 93 
 
 Mum 93 
 
 Fimbriaria 85 
 
 flavescens 88 
 
 flagellata 52 
 
 fragilis 39 
 
 fryei 80 
 
 fringillarum 93 
 
 fuligulosa 93 
 
 fusa 59, 93 
 
 furcifera 38, 45, 92 
 
 f urcigera 93 
 
 glandularis 52 
 
 globocephala 52 
 
 gracilis 52, 62 
 
 groenlandica 93 
 
 Haploparaxis 21, 92 
 
 hemignathi 38 
 
 hirsuta 93 
 
 himantopodis 38 
 
 Hymenolepis 12, 23, 26, 29, 38 
 
 Hymenonmbria 85 
 
 ibidis 54 
 
 importata 54, 64, 72 
 
 inermis 40 
 
 inflata 54, 89 
 
124 
 
 ILLINOIS BIOLOGICAL MONOGRAPHS 
 
 |124 
 
 intermedia 54, 86 
 interrupta 54, 55, 64 
 interruptus 80 
 introversa 55, 67 
 jaegerskioeldi 53 
 kowalewski 40 
 kempi 42 
 Ianceolata 41, 59 
 larina 93 
 
 lateralis 23, 53, 56 
 liguloides 54 
 linea 40 
 liophallos 93 
 lobata 54, 72 
 lobulata 23, 39, 43 
 longicirrosa 38 
 longirostris 53 
 longivaginata 38 
 longivaginosus 34 
 macrocephala 62 
 macrostrobilodes 55, 65 
 macracanthos 48, 93 
 magniovata 54, 65 
 medici 54 
 meleagris 53 
 merganseri 85 
 megalops 53 
 megalorhyncha 94 
 megalorchis 54 
 megalbystera 40, 70 
 microcephala 39, 42 
 microps 55 
 microsoma 53, 59 
 microcirrosa 56, 70 
 microscolecina 54 
 micrancristrota 93 
 minor 93 
 
 multiglandularis 41 
 multistriata 40 
 murmanica 93 
 musculosa 39 
 naja 93 
 nana 84 
 nitida 39 
 nitidulans 39 
 octacantha 54 
 octacanthoides 59 
 Oligorchis 12, 33 
 orthacantha 40 
 orientalis 93 
 
 paculifera 93 
 
 parvula 53 
 
 pachycephala 39 
 
 papillata 53 
 
 parviceps 89 
 
 parina 54 
 
 parvirostellata 93 
 
 paucitesticulatus 37 
 
 passerina 54 
 
 pauciovata 38 
 
 pellucida 54, 65 
 
 penetrans 93 
 
 petrocinclae 75, 93 
 
 phasianina 54 
 
 pigmentata 93 
 
 planestici 55, 73 
 
 podicipina 45 
 
 polygramma 72, 75, 93 
 
 przewalski 41 
 
 pubescens 93 
 
 querquedula 55, 70 
 
 rarus, 53 
 
 retracta, 40 
 
 recurvirostrae, 93 
 
 rectacantha 39 
 
 rhomboidea 93 
 
 rostellata 55 
 
 rosseteri 93 
 
 sagitta 93 
 sacciperium 40, 48 
 septaria 38 
 serpentulus 53 
 serrata 38 
 setigera 41, 59 
 siberica 93 
 simplex 55 
 sinuosa 52 
 sphaerophora 93 
 sphenocephala 53 
 spinosa 29, 38 
 solovriowi 38 
 strangulatus 33 
 stylosa 53 
 styloides 53 
 tenerrima 94 
 tenuirostris 41 
 tenuis 55 
 teresoides 53 
 terraereginae 94 
 tetrads 55 
 
125] STUDIES ON AVIAN SPECIES OF HYMENOLEPIDIDAE—MAYHEW 125 
 
 trichodromia 94 
 trifolium 39, 62 
 tritesticulata 53, 84 
 trichorhynchus 94 
 tubicirrosa 55 
 uliginosa 94 
 uncinata 55 
 upsilon 39 
 uralensis 94 
 variabile 77 
 vaginata 53 
 
 vallei 94 
 venusta 41, 59 
 villosa 39 
 voluta 52 
 Wardium 76 
 Weinlandia 23, 52 
 yorkei 33 
 zosteropis 55, 64 
 
 The chief references to each species 
 genus are indicated by full face type. 
 
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 UNIVERSITY OF ILLINOIS-URBANA 
 
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