THE LIBRARY 
 
 OF 
 
 THE UNIVERSITY 
 OF CALIFORNIA 
 
 PRESENTED BY 
 
 PROF. CHARLES A. KOFOID AND 
 MRS. PRUDENCE W. KOFOID 
 
THE HYDROIDS OF THE WOODS HOLE REGION. 
 
 By C. C. NUTTING, 
 L _ Professor of '/.oology. University of l&uta. 
 
 INTRODUCTORY NOTE. 
 
 The limits of the "Woods Hole region," in the sense hero, used, may be roughly 
 defined as follows: Starting with the point of Cape Cod as the northern and eastern 
 limits, following the New England coast to New London, Conn. ; thence southward to 
 the end of Long Island; thence southeast to the edge of the Gulf Stream, which is 
 followed until off Cape Cod. These limits embrace, roughly, the area that can be 
 covered by one-day excursions by steamer from the U. S. Fish Commission station 
 at Woods Hole, Massachusetts. 
 
 It is the purpose of this pamphlet to furnish collectors and workers in this 
 region with a practical and concise means of identifying the species of hydroids known 
 to occur within the area above described. There are a number of other species that 
 almost certainly occur within the Woods Hole region, but with one or two exceptions, 
 involving species of unusual interest, these will be omitted. 
 
 Most of the material studied in connection with this work was secured by the 
 author during three summers spent at the U. S. Fish Commission laboratory at 
 Woods Hole and a month at the laboratory of Dr. Alexander Agassiz, at Newport. 
 
 The number of species listed indicates a fairly rich hydroid fauna in the region, 
 the general relation being with the Arctic or rather Ilolarctic fauna, which explains 
 the large percentage of British forms represented on our Atlantic coasts. 
 
 The illustrations are from sketches originally made by the author to illustrate a 
 monograph of the North American hydroids, in course of publication by the United 
 States National Museum. Permission was given by the authorities of that institution 
 to have ink tracings made from these sketches, which have been reduced in size and 
 used in the present work. 
 
 In order to secure the brevity necessary for the treatment of the subject in the 
 form of a practical guide to identification, it has been necessary to omit all discussion 
 regarding synonomy. In naming genera and species a conservative course has been 
 followed, although the names in some cases have been changed in what will doubtless 
 appear to be an arbitrary manner. The reasons for these changes are in -all cases 
 briefly indicated, but the explanations are not so full as would be deemed requisite in 
 a Work of more strictly technical nature. 
 
 Much remains to be done before we can discuss with profit the economic bearings 
 of the subject of this work. It is well known, however, that many fishes feed more 
 
 828 
 
 M368791 
 
in UKTIN <>K Till-: LfNITKl) STATUS FISH rn.\l.\l issiu.N. 
 
 or less extensively on hydroids. Dr. Kdwin Linton has several times called my 
 attention to the fact that he often finds hydroids in the stomachs of fishes while 
 examining them for parasites. 1 am inclined to think, however, that hydroids do 
 not constitute a very important item in the dietary of our food-fishes, and am rather 
 of the opinion that the economic importance of hydroids lies in the fact that the 
 presence of these forms in quantities in a given region is of value as an indication of 
 abundance of food for fishes in the shape of small crustaceans. It is known that 
 many kinds of hydroids live very largely on minute crustac-ea, and it follows that 
 Where the hydroids thrive the fishes will also lindan abundant food supply, especially 
 in the earlier stages of their development. 
 
 The author -is indebted to many naturalists for material that he failed to securo 
 himself, and has endeavored to briefly acknowledge these fcivors in their proper- 
 connection in the body of the text. 
 
 STATK I'MVE'UMTV OF IOWA, Ani/uxl 10, 1900. 
 
 Kill In /III' J'ililli/ii-x nf Ill/ilroiiln fiill'iul in Hi," U'lHiilx Hull' fi'i/ifin. 
 
 A. Hydranths anil >:' mophores not provided with special chitinons receptacles. 
 
 a. Hydra n ills with MM I tern I lilil'cirni tentacles CI.AVID.K. 
 
 <('. Hyilruuttis with u single whorl of li!il'(ini] lenlaclcs. or two or more closely approximated whorls. 
 
 around base of proboscis, which lni.i, r l]l easily he mistaken for a single wliorl. 
 b. Proboscis conical. 
 
 o. Colony regularly branched BotjGAisviu.iDvE. 
 
 <'. Colony not branched. 
 
 tl. Hydrorhi/a- composed of incni.stintt, aillierenl tubules overlaid with a Him of I'lenosarc. 
 
 HYDRACTIXIDJ:. 
 
 '/'. Hydrorhizie not mutually adherent and not overlaid with n layer of co-nosarc PODOCORYNI&4E. 
 
 //. I'roltoseis trumpet-shaped or hemis|iherical. the distal portion beinif the bell of tile trumpet or 
 
 e<in:itor of I lie hemisphere EUDENDKID.S. 
 
 '.i". Hydranlhs w'ith more than <-:ie w liorl of liliform tentacles. 
 //. A dislinet tube of horny perisan' around the stem. 
 
 <. Distal tentacles in two distinct whorls TITBULARID.*:. 
 
 f. Distal tentacles not in two .list inn horls HYBOCON1DJ!. 
 
 /i'. No distinct j.erisarcal tube: stem conspicuously cunaliculated: probosiMs large COEYMORPHID*. 
 
 '". Hydrant hs with e.ipitale tentacles only SYNCORYNID*. 
 
 a"". Ilydranths with a basal row of filiform tentacles, and with capitate tentacles on the proboscis PENNARID*:. 
 
 A'. It'ydranths and iionophores provided \\ itli special ehitinous reeejitacles. (Hydrotheca- and ^onangia.) 
 o. Hydrotheca- \\ith distinct pedicel, anil with a septum partly dividinn the hydrothecal cavity from 
 
 the cavity of the pedicel CAMPANULARID*. 
 
 a'. Hydrothec;e with an opercnlnm compoKed of con verging seKinents CAMPANULINID^:. 
 
 a". Hydrotliee:e deep, witli pedicels: or ses/ile, and without the septum LAFOSID^:. 
 
 ii'"'. llydrotheea- reduced to saucer-shaped hydrophoivs ornamented with a necklace of bright dots, 
 
 and much too shallow to accommodate the hydranths HAI.ECII>.E. 
 
 <"''. llydrotheea- sessile, mid adnate by their sides to the branches on which they are placed. 
 
 l>. llydrotheea- arranged OTI lj->th sides o! the branches SERTULARID^. 
 
 ' I,'. Hydrothcea- arranged on KM side only of the branches PUIMULAR1M5. 
 
 CLAVIDAE. 
 
 Trophosome. Ilydroraulus lininrhi'il, simple, or not evident. Hydranths with elongated terete 
 bodies, upon which the smooth filiform tentacles ;uv sriitu-ivd, or arranj;ed in an ill-<lefined spiral. 
 
 <inii,ixiin\ Gonophores growing from the hydrorhiza, hnuiclu's, or body of the hydranths, am^ 
 
 not pniihicin;' OIT mcihisiii 1 . 
 
 Ki'if tn t/i'ni'i'ii f f ' '/tii'!'/:r I'nnilff ill Woodt lft>l< I'l'tjuni. 
 
 rolony un branched. ll\ - di'anth si ems not inclosed in perisare:il tubes Clara. 
 
 Colon > profusely Immcli-.l fimvlytophnrn. 
 
.' OJB 1 Till WOOD.S HOLE UKGIOJT. 
 
 CLAVA, 
 
 327 
 
 Tropltnxnmf. Ilydranths single, with slender basal portions ami terete hod it's. Filiform tentacles, 
 about 20 to 30 in number, pcam-red over the body and proboscis. 
 
 Qtmofome. Gonophores home in clusters Immediately below the basal tentacles. 
 
 Clava leptostyla Agassi/. Fig. 1 . 
 (Contribution-; to tlir Natural History of Die United States, 1862, iv, p. 218.) 
 
 Trophosnmi'. llydranths with a slender proximal portion and a long distal proboscis; tentacles 
 more than 20 in full-grown specimens, hydrorhiza forming a closely aggregated ineshwork of con- 
 tiguous tubes. 
 
 Gmiosome. Gonophores borne below the proximal tentacles in compact clusters, which may 
 encircle the hydranths or be nnsvinmetrically collected on one side. 
 
 Color. Brick-red. 
 
 Distribution. Has been found on the rocks near the Hole, where it occurs in patches under the 
 seaweed. I have also found it attached to the piles of the old guano wharf. 
 
 Under the head of "distribution," localities are given where the species have been found in the 
 Woods Hole region. 
 
 2. Carili/lapham laauitris Alltnan. 
 
 CORDYLOPHORA. 
 
 Trophosome. Colony regularly branched. Hydranths with scattered filiform tentacles. 
 Qonosome. Gonophores borne on the branches, ovate, inclosed in a chitinous investment which 
 resembles a gonangium. 
 
 Cordylophora lacustris Allman. Fig. 2. 
 
 (Brit. Assoc. Rep., 1843.) 
 
 Trophnsomi'. Colony regularly branched, attaining a height of about three-fourths inch. Main 
 stem not fascicled, straight, giving off alternate branches, which in turn often give off alternate branch- 
 
328 
 
 HKLLKTTN OK THE UNITKD STATES FISH OOMAUhSiUN. 
 
 Iris ami pi-diivls; branches and pedicels often annotated at their origins. Hydranths \vitli fusiform 
 bodies and 16 to 20 scattered filiform tentacles. 
 
 t.'iiiiiixiiiiif. Gonophores ovate, invested in a gonH&ghim-like extension of perisarc, borne on the 
 branches an<l hydrant!) pedicels near their bases. Pedicels of gonophoret very short and annulated. 
 
 l>ixti-!liiit!<in. Found in a fresh-water pond near the bathing beach at Woods Hole, Mass. 
 
 This species is reported from the Woods Hole region just as these pages are going to press. The 
 figure ami description are from specimens collected by Prof. A. I). Morrill and kindly forwarded to me 
 by Dr. Charles llargitt. 
 
 yne mirabttis (Ag.). A. Sessile medusa ( 9 ) 
 B. Sessile medusa (<f ). 
 
 SYNCORYNin^E. 
 
 <sj 
 
 4. Gtrifniiis ngaKsizu McCr. 
 (After Murbaeh.) 
 
 Trophosome. Hydranths with capitate tentacles only, scattered over the 1 eliktgated body or 
 growing in more or less distinct verticils. 
 
 Oonosome. Gonophores usually borne above the bases of the proximal tentacles, and producing 
 attached or free medusse with 4 radial canals and 4 tentacles with bulbous- bases, and a deep bell. 
 
 Key to genera of Syncorynidx found in the Woods Hole: region. 
 
 A chitlnous perisare investing the stem. Hydranth body shorter than stem when .expanded Syncoryne. 
 
 No chitinous perisarc. Hydranths sessile, with long cylindrical bodies Corynitit. 
 
 SYNCORYNE. 
 
 Trophosome. Hydrocaulus well developed, often branched and more or less annulated. Hydranths 
 with numerous stout capitate tentacles and terete bodies. 
 
 Gonosome. Medusse as described above, bulbous bases of tentacles often with dark eye-spot. 
 
HYDRO!!)* OK THK WOODS Hof.K RKOTON. 329 
 
 Synceryaa mirabilis ( Ay. ). Fig. '.'. 
 
 i fin-inn iiiinihillf Ajjassix. Cunt. Nut. Hist. I". S,, IV. p. 185.) 
 
 r. Colony irregularly branching, without distinct hydrorhiza. Hydranths with terete 
 body and about lt> stout capitate tentacles. Perisare not annulated. 
 
 <;,,unxntne. Mcdus;e borne on the hydranth body, with 4 radial canals and 4 marginal tentacles, 
 which are rudimentary and without evident eye-spots in the sessile medusae, and a very large proboscis 
 on which the sexual elements an; produced and east forth before the medu.se become free. The free 
 medussc are more hemispherical in shape and have fully developed tentacles with eye-spots on their 
 bases, and the proboscis is much smaller. 
 
 < b/OT-.-^UuJwps rose-red owing to color of lining of body cavity. 
 
 fHntrihutiim. Found attached to rocks, seaweed, and floating timbers (A. Agassi?.). Specimens 
 were found in both the II. S. Fisli Commission and Marine Biological Laboratories, but the labels did 
 not indicate the localities. Waquoit. ( Vinal Kd wards. ) 
 
 CORYNITIS. 
 
 Trr>)ili<>x<n:ii'. No evident perisarc. Colony consisting of single cylindrical hydranths with 
 spirally arranged capitate tentacles. 
 
 (tintrmime. Gonophores on hydranth body producing medusa' with two tentacles which bear- 
 stalked batteries of ncmatocysts. 
 
 Coryuitis agassizii McCrady. Figs. 4 and 80. 
 i I'riicoedings Elliott Suck'ty. vol. I. No. 1, p. 132.) 
 
 Tm/iluixoini: Colony not branched. Hydranth with a long, cylindrical body and spirally 
 arranged capitate tentacles. 
 
 Gommonif. Gonophores growing low down on the body of the hydranth. Medusa? almost 
 spherical, the surface dotted with clusters of nematocysts. Marginal tentacles 2 or 4, with swollen 
 bases and thickened ends. Ovaries on basal portion of the proboscis. Mouth lobed. 
 
 Color. Medus;e with manubrium, eye-spots and ends of tentac.les red. Ovaries orange red. 
 
 rHxIriliiillon. Found at Woods Hole. (Dr. Murbach.) 
 
 I have not seen this species, but Dr. Murbach has kuidly allowed tracings to be iriade from his ' 
 drawings, to be used in this work. 
 
 BOUGAINVILLIDjE. 
 
 Tri>/iliimiinf. Colony branching (in our species) and with a distinct hydrocaulus. Ilydrantha 
 with a dome-shaped or conical proboscis, and a single whorl of rigid filiform tentacles. 
 
 Gonomine. Gonophores borne on hydrocaulus below the hydranth body. (Never from the 
 hydrorhiza in our species.) Medusa with 4 radial canals. Marginal tentacles either single or in 
 clusters, with sense bodies at their bases. 
 
 In iji'in'fii < if lliiin/iiiiii -il/itl;!' found in tlte Wiiorlx Hole region, 
 
 Hydroeaulus with a strongly marked ohitinons perisarc. Medusse with clustered marginal tentacles and 
 
 ramitk'd mouth tentacles ............................................................................... Sougmnrillia. 
 
 Hydronuihis\vithagelatiiKius]iei-isiire. Medusar with asinglc marginal tentacle, and jio mouth tentacles.. Pm';/"" '''""" 
 
 BOUGAINVILLIA. 
 
 Troplwsomf.. Perisarc strongly marked, branched, and ending below the bases of the tentacles of 
 the hydranths. 
 
 Gonosomr. Gonophores borne on pedicils springing from the hydrocaulus. Medusa; with 4 
 pairs of marginal tentacles when first set free, afterwards with 4 clusters of tentacles, each tentacle ' 
 with a black eye-spot above its base. 
 
 Key to species of Bangui, irilliii fmmd in Hie Woods'Iffie region. 
 
 Hydranths with small proboscis and 15 to 20 tentacles. Medusae with very broad proboscis ............. S. stipertiliaris. 
 
 Hydranths with conspicuous conical proboscis. Medusae with a narrow proboscis ....................... B. carolinmsii. 
 
330 
 
 BULLETIN OF THE UNITED STATES FT8H COMMISSION.. 
 
 Bougainvillia superciliaris A<;. tfkr. ill. 
 
 i Com. N'iil. Hist. ('. S.. IV, p. '.Ml. I 
 
 Tropltoxiniif. Colony attaining; a height of about 2 inches-. St(-m not I'asciclcd, irregularly 
 branched, branches and branchlets often aimulated proximally. Hydranth.s with very inconspicuous 
 proboscis and 15 to 20 rigidly disposed tentacles. 
 
 Ganutome. Gonophores borne mostly on the ultimate branches. Mature medusa- with a very 
 broad and heavy proboscis and much ramified mouth tentacles. Each cluster of marginal tentacles 
 with a large sense-bulb at its base. 
 
 Color. Colony light brown with a greenish tinge. Ilydrunth body witli a suggestion of rose 
 color. Medusa 1 with a pale-yellow proboscis tinged with red at the end. t-Vnse bodies orange-red 
 surrounded with yellow. 
 
 DittributitM. Newport, R. I., attached to fucus and shells. Wo<ds Hole. 1 have not seen the 
 trophosome of this species and have culled the description from that of Dr. Alexander Agassix. The 
 medusa was taken by me at Woods Hole on August 1 1, ISlill. 
 
 5. Bovgoinvima carollneMti iMeCr.) 
 
 *. iniu*i Osliorn & Hurgitt. 
 
 Bougainvillia carolinensis (McCr. ). Fig. 5. 
 (Hippocrctic carotinemis McCracly. Proc. Elliott Soc., vol. I. No. 1, p. Nil. ) 
 
 Trophosome. Colony attaining a height of 12 inches, but usually 3 to (i inches, and branching 
 much as in the preceding species. Hydranths growing on both main stem and branches, with a long, 
 prominent, very flexible proboscis, which may be a lengthened cone, or may be rolled back until it 
 assumes a saucer-like shape; tentacles not more than 12 in specimens examined. 
 
 Gonosome. Gonophores borne on both main stem and branches, often in clusters. Mature 
 medusae much like the last, but with a short and narrow proboscis. 
 
 Color. Colony light brown with greenish tinge, hydranth body with reddish tinge. Medusae 
 with brick-red proboscis and sense-bulbs red surrounded by green and yellow. Eye-spots jet-black. 
 
 Distribution. Growing on the piles of the U. S. Fish Commission's dock at Woods Hole, and 
 common in the vicinity. It is often found attached to fncua and floating timber. 
 
llVDltolDS OK THE WOODS HObK KK<ilo\. 
 
 PEBIGONIMUS. 
 
 .. Colony attaining a height of about 1 inch, either branched or simple; perisarc of a 
 jelly-like consistency and reaching to the bases of the tentacles. Hydranth body terete, the proboscis 
 being large and conical. 
 
 (iiniiixiinii: I loiiophoivs borne on the branches or hydranth bodies, in our species. Medusa; bell- 
 shaped, with a simple or lobcd proboscis. Marginal tentacles 2 or 4, not in clusters, and with bulbous 
 bases and no eye-spots. 
 
 Perigonimus jonesi Osborn & Hargitt. Fig. (i. 
 (AmiTioln Naturalist, vol. xxvm. p. '27.) 
 
 1'm/iliiixiiiiii'. Colony attaining a height of about one-fourth inch, freely branching, the branches 
 erect and continuing insensibly into the hydranth body; gelatinous perisarc very thick and often 
 wrinkled, reaching to the bases of the tt-sitacles, and sometimes appearing to include the proximal 
 part of the latter. Ilydranths with about 1(1 tentacles held rigidly, but alternately depressed and 
 elevated; proboscis dome-shaped or snbconical. 
 
 GonOMnnr. (ionophoros borne' on the hydranth body or branches. Medusa! ovoid, with 2 
 tentacles, 4 radial canals, and 4 eye-spots; rnanubrium short with a 4-lobed mouth. 
 
 Co/or. Colony flesh-colored. 
 
 I>ixtrilnitiii. Found on the abdomen and walking legs of Luliinin > imirffhiata. Collected at 
 Coldspring Harbor, Long Island. 
 
 This species does not come strictly within the Woods Hole region, but as it is the only American 
 Peri(/iiiiiiiiiin vet dcscrilx'd it. seemed desirable to include it here. 
 
 7. Kiidrinlritiiii tm HUSHM Linn. A. Hydranth bearing female gonopnorea 
 
 - 
 
 EUDENDRID^E. 
 
 Trophosome. Colony branching, often profusely; perisarc evident, often regularly annulated. 
 Hydranths with a single verticil of filiform tentacles, and a proboscis that is at times trumpet-shaped 
 and at times hemispherical, the 'distal end being the larger. 
 
 Gonosome. Gonophores (male) forming verticils just beneath the tentacles of the hydranth, each 
 verticil being composed of a number of gonophores radiating like the spokes of a wheel, each gono- 
 phore having 2 to 4 chambers in linear series; female gonophores not in regular verticils, and usually 
 clustered around the hydranth bodies. No medusae. 
 
332 m'LUvUN I CED STATES rl^ll COMMISSION. 
 
 EUDENDBIUM. 
 
 Characters of the family as given above'. 
 
 A"*'*/ In xjH'fit'X of EudttldriWH /i"'//'/ in fix' 1\'ttIs Hull' i'i'<jnm. 
 
 A. Main stem fascicled. (Larger spccii-s.i 
 
 a. Stem and branches extensively annulated throughout. Hydranth b**ly vasilVrnt E. <.U*iia?. 
 
 a'. Branches and pedicils annulnted at proximal ends only. 
 
 6. Colony large, pinnately branched 1 . Male gonophores with 2 or Schamliers E. ramosuw. 
 
 b f . Colony smaller, less than 3 inches. Male gonophores 4 or 5 clunnbered and borne on atrophied 
 
 hydranths E. car it f nut. 
 
 A'. Main stem not fascicled. (Smaller species, i 
 
 n. Hydranth body globular; pedicils long, slender. Male gonophores 4 or 5 chambered E.tenuc. 
 
 '. Hydranth body vasiform, colony bushy; pedicils siren;:, shorter. Female gonophorcs on aborted 
 
 hydranths E. capillare. 
 
 <i". Hydranth body vasiform: colony minute, about one-fourth inch, sparsely branched; pedicils very 
 
 long, slender and pellucid. Uonuplmrc* Ixmic on aborted hydranths E. uttimn. 
 
 Eudendrium ramosum 
 (Linn.) Fig. 7. 
 
 (Tltbtttui-iit runt"*! Linn.. Syst. X;tt., 
 p. 13t.) 
 
 Troplitinniie. Colony 
 bushy, attaining a height of 
 & inches; stem fascicled, the 
 main branches giving off 
 pinnately disposed branch- 
 lets; annulations confined to 
 bases of internodes and ends 
 of pedicils. Hydranth body ovoid. 
 
 (liiwisoine. Male gonophores borne on bodies 
 of hydranths that are not often completely aborted, 
 2 or 3 chambered; female gonophores borne usually 
 on hydrantlis below tentacles, or on upper part ot 
 pedieils. 
 
 Cnlnr^ General color greenish. The hydrantli 
 todies lined with vermilion pigment. Male gono- 
 phores vermilion; female gonophores orange red. 
 
 Dixirilintiiin. Growing abundantly on piles of 
 U.. S. F. Co. wharf at Woods Hole. One of the com- 
 monest forms nourishing in shallow water. 
 
 B. 
 
 A. 
 
 S. Kililfinti-hiHl i 
 
 Eudendrium dispar Ag. Fig. S. 
 (Com. Nat. Hist. r...,iv,p.ais.) 
 
 Trni>h<ixnin>'. Colony large, attaining a height of "> inches. Stem slender, slightly fawiclexl, with 
 extensively annulated branches and pedicils. Hydranth body vasiform. 
 
 (liiiiimiiiif. (ioiKijihores Ixirne on hydranths, which are not aborted anil nstmlly not reduced 
 in size. 
 
 Ciilor. General color greenish. Hyxlranths tose-colored. Male goronphores orange; female 
 gonophorea pink. 
 
 Dixti-ilmtiiiii. Found in rather deep, clear water. Naushon. (A. Airassix). ('. S. Fish Commission 
 station 7CM0. off Bloek Island. (Nuttins.'. i 
 
r- Of THK WOODS ][tiu-. UKi 
 
 333 
 
 Eudendrium carneum Clarke. Kijr. it. 
 (Mem. Boston Soo. Nnt. Hist., in, No. -I, p. 137.) 
 
 e. Colony attaining a lieight of about 2 inches; main stem fascicled, pinnately 
 branched, the branches not so widely spreading as in K. ramowm. Ampliations usually confined to 
 the proximal ends of branches and pedicils, except that the pedicils bearing aborted hydranths and 
 gonophores are deeply ringed throughout. Hydranth body subvasiform. 
 
 Gonosome. Male gonophores 4 or 5 chambered, borne in a verticil around the body of aborted 
 hydranths, which are themselves joined to pedicils bearing ordinary hydranths, the two being thua 
 borne in pairs symmetrically disposed on the branches. 
 
 f Wo*-. Hydranth bodies and gonophores bright red. 
 
 Dintribulion. The specimen described was found in the U. P. Fish Commission collection at 
 Wood* Hole. Labeled December 17, 1888. 
 
 9. Etidcndriinn rarnritm Clarke. 
 
 10. Etukndriam tenvc A. Ag. 
 
 Eudendrium tenue A. Ag. Fig. 10. 
 (North American Acalephse, p. 100.) 
 
 Tropliosome. Colony branching irregularly, attaining a height of about one-half inch. Stem not 
 fascicled, loosely branching, the pedicils being long and slender. Hydranth body globular. 
 
 Gonosome. Male gonophores 2 to 4 chambered, borne on nnbranched annulated pedicils, the 
 hydranths of which have become aborted. Female gonophores globular, scattered over hydrantto 
 body and pedicils. (A. Agassiz. ) 
 
 Color. General color bright pinkish. (A. Agassiz. ) 
 
 FHitribtition, Shallow water in Buzzard's Bav. Xauslion. 
 
334 
 
 BULLETIN OF THK UNITED STATES FISH COMMISSION. 
 
 Ettdendrium capillare Alder. 
 (Catalogue of the Zoophytes of Northumberland and Durham, p. 105.) 
 
 Trophosoine. Colony attaining a height of about one-half inch, sparsely branching, the branches 
 and pedicila being sparingly annulated. Hydranth body vasiform. 
 
 < iononome. Male gonophores 2 or 3 chambered, borne on aborted hydranths springing either from 
 the branches or hydrorhiza. Female gonophores also borne on aborted hydranths. 
 
 Color. Bydranths pale greenish. Male gonophores orange. 
 R. I., in shallow water. (C. C. N.) 
 
 11. J-lttdcndi-iitm album Nutting. A."_Hydfanth with male gonophores. 
 
 Eudendrium album Nutting. Fig. 11. 
 (Annals and Magazine of Natural History, May, 1898, p. 362.) 
 
 Tropliozome, Colony minute, attaining a height of about one-third inch, branching in a strag- 
 gling manner, the ultimate branches or pedicils being exceedingly long and slender, pellucid, and not 
 decidedly or regularly annulated. Hydranths with vasiform bodies. 
 
 Gonosomc. Male gonophores 2 or 3 chambered, borne on hydranths that are generally not 
 aborted, but may be considerably reduced in size. Female gonophores apparently not so numerous as 
 in allied species, borne on partially aborted hydranths. 
 
 Color. General color white, hydranths almost entirely so. Male gonophores pale orange yellow. 
 
 Distribution. Found on floating seaweed secured in taking the tow at Woods Hole; also on U. S. 
 Fish Commission wharf. 
 
 HYDRACTINID^E. 
 
 Trophoeome. Colony formed of "persons" of three sorts springing from an incrusting layer 
 beset with jagged spines. Perisarc not evident. Hydranths with a single whorl of filiform tentacles 
 and a conical proboscis. "Spiral zooids" or defensive persons slender, cylindrical, spirally coiled, 
 with large nematocyst batteries near their distal ends. 
 
 Gonosome. Gonophores fixed sporosacs borne on blastostyles, forming a thin! or sexual person of 
 the colony. 
 
 HYDBACTINIA. 
 
 CharactiTH of the family us 
 
 above.' 
 
OF THE WOODS HOLK KKWION. 
 
 335 
 
 Hydractinia polyclina Ag. Fig. 1 2. 
 ((Vint. Nat. Hist. r. s., iv, p: >7J 
 
 Ti'iiiiliiuaiini'. Colony composed of thickly crowded persons arising from an incrusting plate beset 
 with jagged spines and overlaid with crenosarc. Hydranths slender, gradually increasing in size 
 from proximal to distal end, tentacles 
 numerous, filiform, arranged in sev- 
 eral closely approximated whorls, 
 which are so closely set as to appear as 
 one whorl at the base of the rather low 
 conical proboscis. Spiral zooids gen- 
 erally situated on the borders of the 
 colony and with a number of nenta- 
 tiM'yst batteries around the distal end. 
 
 ( !oii iixut/i i'. Gonophores borne 
 on sexual persons which are much 
 stouter and shorter than the hy- 
 dranths, and have numerous batteries 
 of nematocysts around the conical 
 proboscis, but no tentacles. No free 
 medusa'. 
 
 f'lilnr. Hydranths white, tinged 
 with red. Gonophores, which give 
 the characteristic color to the colony, 
 bright red. c ^ 
 
 Dintriliutiim. Found growing on ,,, //,,;.,.,//,,,,,,/ Ag '. A . Nutritive " person."' B. Repro- 
 
 gaataropod shells inhabited by hermit rim-tire persons, c. Spinal zooids on fighting persons. 
 
 crabs, on the bare rock, or on the piles 
 
 of wharves. The writer has found them among the colonies of Tiiliulru-tacroctaon the V. S. Fish Com- 
 mission wharf at Woods Hole. 
 
 I have carefully compared this species with //. rcliiiidla from England, and found that the two 
 are quite distinct as claimed by Agassiz. Aside from the characters as given by him I find that the 
 European form has very much larger hydranths than the American, and much less numerous tentacles. 
 
 PODOCORYNIDJE (modified). 
 
 Trophusome '. Hydranths with a single whorl of filiform tentacles around the base of a conical 
 proboscis. Hydrorhiza a reticulate network of stolons invested with perisarc and usually l>eset with 
 jagged spines. 
 
 floiiotome. Gonophores growing in a circlet around the basal part of the hydranth body, and 
 producing fixed sporosacs or free medusa? with 4 radiating canals and 4 or 8 marginal tentacles with 
 eye-spots at their bases. 
 
 STYLACTIS. 
 
 Ti-ophosome. Hydranths sessile, without evident perisarc, slender, growing from a hydrorhiza 
 composed of a network of anastomosing tubes which are not covered with naked ccenosarc, and which 
 usually bear chitinous spines. 
 
 fJoniisiitiie. Sporosacs borne on the hydranth body just below the tentacles, and producing 
 medusa: with 8 rudimentary 'tentacles and no mouth. 
 
 Styiactis hooperi Srgrrlbw. Figs. 13 and 86. 
 (American Naturalist, xxxm, No. 394.) 
 
 Tropltosome. Hydranths exceedingly slender and attaining a height when alive of alxitit three- 
 fourths inch. Tentacles in a single whorl, very variable in number, the average, according to Sigerfoos, 
 being 18 to 25. Hydrortma covered with a felting of diatoms, etc., but with no covering of naked 
 ccenosarc. 
 
330 
 
 Hl'l.l.KTl.N OK THK I'NITKD STATKS K'ISH COMMISSION. 
 
 t'liiiiiisoiiu: Gonophores borne on shorter hydranths just below the tentacles and producing free 
 meduste with 4 radial canals, 8 rudimentary tentacles, and neither mouth nor eye-spots. Ova borne 
 on the very large manubrinm.. 
 
 13B. 
 
 13. Mytnrti* hnoitfri Sigerfoos. 
 
 A. Nutritive hydranth or "person." ~ 
 
 B. Reproductive hydranth or "person." 
 
 14. Pfntmria ttai-elfa McCr. 
 
 A. Branch of colony. 
 
 B. Hydranth with medusae (enlarged). 
 
 C. Single sessile medusa' (enlarged) . 
 
 Color. A. specimen kept for some time in formalin is of a reddish flesh color. I have not seen 
 the free medusae, and the color is not given by the original describer. 
 
 Distribution. Found on shells of a living gasteropod, Ilyanasxa obsolete!. A colony was found at 
 Woods Hole in 1886. Dr. Sigerfoos found numerous specimens at Coldspring Harbor, Long Island. 
 
 PENNARID^E. 
 
 oinr. Colony regularly branched (in our species). Hydranths with a proximal circlet of 
 filiform tentacles and a distal set of spirally arranged or whorled capitate tentacles. 
 
 GfHioaome. Gonophores producing medusa; which are either attached permanently or become 
 free when mature, and which have 4 radiating canals and 4 rudimentary tentacles. 
 
HTDROID9 OF THK WOODS HOLK 
 
 337 
 
 PKNNAKIA. 
 
 Tfii/iliiuuiiin: Colony ]>innately branched, with a pronounced chitiuous periaarc. Ilydranths with 
 a pyrifonn body and long mobile proboscis beset with capitate tentacles. 
 
 (iniKMiini'. Gonophores borne above the proximal row of tentacles. Medusie oblong ovate, 
 with a very large proboscis bearing the sexual products. 
 
 Pennaria tiarella McCr. Figs'. 14 and 84. 
 (l>ro(w<liiiK* Elliott Soc.. vol. i, No. 1, p. I."*!.) 
 
 Ti-ii/ihiHttiitii: Colony attaining a height of about 6 inches, with main stem and branches geniculate 
 and beautifully annulated above origin of each branch, branchlet, and pedicel. Hydranths large, the 
 ones terminating branches being decidedly larger than the 
 others; a basal whorl of about 12 filiform tentacles, and a 
 number of capitate tentacles disposed in indistinct whorls 
 on proboscis. 
 
 (lonosvmr. Gonophores attached to hydranth body 
 just above whorl c >f filiform tentacles, and producing oblong- 
 ovate sessile mednsje which sometimes give forth sexual 
 products while still attached, and sometimes l>ecome free 
 before giving forth the sexual products. 
 
 Color. Stem horn brown with darker areas at the 
 annulations. Hydranth body lined with vermilion, which 
 shows through, producing a beautiful contrast with the 
 white tentacles. Sessile niedusic greenish with vermilion 
 markings. 
 
 DixtrlliHttdn. Abundant on the piles of Fish Com- 
 mission dock at Woods Hole, and also growing profusely 
 on eelgrass near the Hole. One'of the most abundant and 
 lieautiful species on our coast,*. 
 
 CORYMORPHID^;. 
 
 Tmphrmotitr. Ilydranths solitary, without complete 
 tube of perisarc, and having proximal and distal whorls of 
 filiform tentacles, and a number of fleshy or tubular proc- 
 esses on the proximal end of the pedicel or stem. 
 
 fiiniosome. Gonophores producing medusa; which 
 have 4 radiating canals and 1 to 4 marginal tentacles, of 
 which one is much the largest. 
 
 15. Oorymorpha pendtila Ag. 
 
 CORYMORPHA. 
 
 Tni/ihiixome. Hydranth sharply distinguished from 
 its pedicel and with numerous short filiform tentacles 
 arranged in several closely set whorls around the distal end of the proboscis and a single whorl of 
 larger tentacles around the base of the body. 
 
 Cinnoiome. Gonophores borne on branched pedicels above the proximal whorl of tentacles and 
 producing fixed or free medusae with either a single large tentacle or 4^tentacles, one of which ia 
 much the largest. 
 
 Corymorpha pendula Ag. Fig. 15. 
 (Cont, Nat. Hist, U. S., IV, p. 276.) 
 
 Trophosome. Hydranths attaining a height of 3 to 4 inches when alive and fully extended. 
 Pedicel with canaliculated cosnosarc, the canals appearing superficially aa longitudinal banda which 
 anastomose, especially on the proximal part of the pedicel, the distal part of which ia abruptly 
 
 F. C. B. 1899-22 
 
838 BULLKTIN OF THK UNITKI) STATKS FISH COMMfSSlON. 
 
 attenuate and pendant. In place of the hydrorhiza the basal part of the pedicel is frayed out, :is it 
 were, into numerous hollow tubular processes. 
 
 diiniixiiiii;'. Gonopbona borne on branched peduncles inserted aliove the |>roxiinal row of 
 tentacles'. Medusa 1 with 1 large tentacle and usually 3 much smaller ones. 
 
 I'd/nr. Ilydrauth body mid gonophotOB bright pink. Medusa with light-yellow proboscis and 
 pink tentacle bulbs, 
 
 Distribution. Sandy and muddy bottoms in rather deep water. The specimens in the 1*. S. Fish 
 Commission collection at Woods Hole tire not labeled, but are said to be from .Smith Hole. 
 
 TUBULARID/E. 
 
 Ti-n/ilna>iiiiii'. Hydrocaulus with a distinct tubular perisarc, branched irregularly or not at all. 
 Hydranths with a proximal and distal set of filiform tentacles. An adherent, creeping hydrorhiza 
 often produced, 
 
 doiniKdiiii'. (ionophores borne above the proximal whorl of tentacles on branched peduncles, and 
 not producing free medus;e. The female*) produce hydra-like actinules which develop directly into 
 new colonies, 
 
 J\i'jl to tin' i/fiient nf T"l>iil>'idtf fnninl in tlif WiHxl* IIn/i' ri'i/inn. 
 
 Hydrant I;* permanently attached by a regular Imlrorhi/.a Tnl>ttl<tri<i. 
 
 Hydranths nut permanently tixed. tin- stem i>r pedicel giving nit buds from its frit- end, which nri; 
 
 se[ut rated by s[nnitanoiMis fi-ion and develop into new hydra nths Hi/pttlittiii. 
 
 TUBULARIA. 
 
 Tfiijtliiuainii'.- Colony branched or unbranched, attached by jiermaiient chitinous hydrorhiza. 
 (liiiioHiniii; (ionophores borne in pendent clusters attached by i>eduncles to the hydranth body 
 al>ove the proximal tentacles. Female gonophores producing actinules. 
 
 A"' 1 // tn tin' x/icrii'X nf Tiiliiiliiflu fiininl in tin' WI/IH/K I fi>li' ri'ijinii. 
 
 A. Sessile nu'dusiu \vith distinct nidial pna]s and apk'al p^K?t's^e8 T. ntflifmifi. 
 
 A.'. Senile intrinsic without (listiivt nidial canals, and with conical apical processes. 
 
 n. Cu'iiosarr forming a distinct expansion in the stem just below the hydranth. Perisarc exten- 
 sively anmilatco! , T. litri/tis. 
 
 (('. I'eriKare not extensively annulated. 
 
 ft. Hydranths large. Habitat, slidllow water 7v T. iprrtHbilis. 
 
 >>'. Hydninths small. Haliitut, lU-Mji water T. tenella. 
 
 A". Sessile medusie without distinct riwliul canals, and with apical pnx'esses of females flattened. 
 
 Hydrant!)* large. Haliiiiit, shallow water T. croeca. 
 
 Tubularia cithouyi Ag 1 . Kig. 16. 
 
 (Cimt. Nat. Hist. U.S., IV, p.2(!li.) 
 
 Ti-11/ilniKftnn: Stems unbranched, often annulated, attaining a height of 5 to ~! inches. Hydranth 
 large, probably the largest on our coasts, often expanding an inch or more; proximal whorl of tentaclea 
 30 to 40 in number; distal set very much smaller and shorter. 
 
 (iiiiiiiKiiiiii: (Jonophores growing in dense racemes from the hydranth body just alx>ve proximal 
 whorl of tentacles. Sessile medusje with 4 radial canals and without tentacular processes at the oral 
 end. Females producing actiuules. 
 
 Culm: Stem and gonophores bright scarlet. 
 
 Dutribution. Found in brackish water usually. A number of beautiful specimens were sent me 
 by Dr. Mead,' of Brown University, who hail them growing in a submerged flatboat at Providence, 
 R. I. A few specimens were taken from a depth of 30 fathoms by the Fixli Hairk in latitude 40 49' 
 45", longitude 70 42'. Mr. George Gray reports them from Quick Hole and off Nobska Point, 
 
 Tubularia larynx Ellis & Solamler. Fig. 17. 
 (Nut. Hist. Corallines, p. 30.) 
 
 Trophoaome. Colony bushy; stems branched and extensively annulated, attaining a height of 1 
 to 1J inches. Ccenosare of the stem forming a curious collar-like expansion below the hydranth. 
 Hydranth with 16 to 20 proximal tentacles, and about the same nnmber in the distal set, 
 
MVDHnlDS OF THE WOODS HOLK !{K<M'IN. 
 
 (iiniiiKiiiiif. Gouophores twrjie in dense clusters, the female without evident radial canals, and 
 with conical tentacular proc^sse.s at tlirir oral ends. 
 
 CH/IH: I'erisarc, jn adult specimens, yellow. Body of hydranths and jrir.ophorcs pinkish scarlet. 
 
 Distribution. Pound on Mcky an 1 shelly bottom.". A number of specimens secured growing 
 OH l-'.ni'i'ii Iri'itii iliffiir and on sea \vi'0 1 at I". S. Ki<h Connnissi m station ~0(iO, Muskcj;at Lift'-Savins; 
 station iH-ariiiir X. by K. .' K. 4.5 miles. Depth, 5 fathoms. 
 
 ^ (\y>. ). Ki<r. 18. 
 i T.'inmiiiH'iiiiiiii >iHi'i<th;i:> \guf?\-/.. Con. Nut. Hist. r. s.. iv. p. 271. i 
 
 Ti-uiiliiiriiiiH'. t'olony invfiularly branclied aixl sparsely annulated, attainiujra hfi<;ht of about 4 
 incites. Ilydranths with about 20 tentacles in the proximal row and nearly the same number in the 
 
 e. As in the last species-, except tliftt tl;e clustan of gonophoreg are larger and longer. 
 Culm-. The st.'ins are very pale; almost white. Ilydranth liody and jronophores row re<l. 
 Jijuti-iliiitiitn. Found on rocks at end of Newport Jslund. At Woods Hole, locality not given. 
 
 ^ 
 
 111. Ttilittlnriit rittlitiiiit!. 
 A. Sossilt- iiif<lusii. 
 
 17. Tnl>nl<irui l(ti-iin.r Kll. it Sol. 
 
 18. TiilialuTin i'lidiiiltilif (Ag '). , , 
 A. Uniuiplinh- ('initiiiiiiiiK nn nctinuU 1 . 
 
 Tubularia tenella (Ag.). 
 
 I TliililllliH-iiiili'ii Iriirlln \K.. Tout. Nut. Hist. I*. S.. IV. |i.2tS!) 
 
 Trii/,li,,taiiiii- Colony very small for this genus, hardly exceeding 1 inch in height. Stems loosely 
 branching, not distinctly aunulated. Hydranths with a proximal row of about 18 tentacles, and about 
 the same number in the distal row. 
 
 ('iinuxHiiH 1 . As in the last species. 
 
 Color. Stem pale, almost white. Ilydranth Ixvdies and gonophores pink. 
 
 Distribution. The open ocean in rocky pools (A. Agassiz). Vineyard Sound, 6 to 10 fathoms. 
 (A. E. Verrill. ) 
 
 The best distinguishing mark of this species seems to be its small size, only about half that of 
 T. xpfctablUs. 
 
 i 
 
840 
 
 HI I.I.KTIN OF TiJK UNITED ATATKS FISH COMMISSION. 
 
 Tubulajria crocea (A-;.). Fig. 1!). 
 
 ( I'urililhni-i-i ,i;n Aj;.. ('out. Xilt. Hivt.r.S., Vol. IV, p. 2 111. ) 
 
 TVopAosojnc. Colony gmwlng JH dense tufts of stems entangled below and separated into long 
 pedicels above, attaining it hs-ighl of Sto4 inches. Stems unbranched or sparsely branched, annulated 
 slightly at .intervals, and invollen just below the liydranth. Hydranth with a body whorl of about 
 20 to 24 tt'ntifles, ami about the same nnmlier in the distal set. 
 
 0onoMflM,->-Goi|ophoics growing in racemes or clusters. Sessile medusae with a group of about 
 four tentacular proccssi s at its oral end, those of the female being laterally compressed. There are no 
 evident radiating canals. 
 
 ( 'nlur, Body of hydranths and gonophores rose red. Stems pale, almost white. 
 
 IHnlriliiiliiiii. Found growing very profusely on the piles of the Fish Commission dock at Woods 
 Hole; also on the piles of the docks at New Haven and other similar places. 
 
 This species i.s exceedingly difficult to distinguish from T. spei-Uibilin. Indeed, little confidence 
 can l>e placed in identification of specimens without mature female gonophores. 
 
 ' 
 
 19. Tiilinl'iriit i-rnrm (A(f. i. A. Cluster of ffonopliores. 20. Hypolytiif i>cregrinut Murb.' "(After Murbach.) 
 
 HYPOLITIS. 
 
 iiitK'. Colony consisting of single hydranths with a long proboscis and a distal and proxi- 
 mal whorl of filiform tentacles. The proximal end of the stem is free. 
 
 (,'oiiiHiiiiiif. Oonophores borne on the prolwscis immediately above the proximal whorl of tentacles. 
 They occur singly and not in clusters in the type specimen. The sessile medusre are long and terete 
 in form, and show no tentacular processes. 
 
 Hypolytus perigrinus Murbach. Fig. 20. 
 (Quart. Journ. Mic. Sci., vol. 42, part 3, p. 341.) 
 
 The generic description above is sufficient to identify the one known species of the genus. 
 Description condensed from original; figure copied from that of Dr. Murbach, with his permission. 
 
 HYBOCONIDAE. 
 
 Trophosonie. Colony unbranched. Stem with a distinct chitinous perisarc, and rooted to a true 
 hydrorhiza. Hydranths large, with a proximal and distal set of filiform tentacles. 
 Cfenosonte. Gonophort; producing free ineduso?. 
 
HYDROIDS OK THK WOODS HOLK UKGION. 341 
 
 Ti'i.jilioHfiiiii: Stt'ia with distinct, deeply anmilatcd cxjtim<jj<>n just below hydrunth. Hydranth 
 with a proximal whorl n\\i\ J,\yq d;stiu.ct bi\t c.losely approximated distal whorls of filiform tentacles. 
 
 GotUMKimr. (Jonophqrtts attac.hpd ^jwi-tly to the hydranth }yOi(]y without the intervention of 
 peduncles, and developing hitft f^ee meduan, each of which has a singly large tentacle bearing suceeed- 
 ing gei\i3\t ions of H\e.(\U<*- Mt^".""' deeply campanulate, with 4 ratljal canals and a short proboscis. 
 
 Hybocodon prolifer Ag. pig. 7<i. 
 {Com. Xnt. Hisl. T. S.. iv, p. -Jl:l. i 
 
 V')v/y/ijn4.(.,t. . - Ilydroeaulus unbranched, longitudinally striped owluu to thu ixeiiosurcal canals 
 showing tlirough; perisarc suddenly enlarging near the hydranth, where a number of collar-like 
 swollen rings api>ear, the uppermost lieing the largest. Jiytlrailth IWK'h h'ke that of Tnlmlanii, but 
 with two distinctly separated whorls of tentacles around the proboscis, each whorl being composed of 
 about 16 tentacles, the lo,\YPV l>t'-i"g twit* s long a" the upper. 
 
 <IHH<UUHH<: (ionophores adnate to the hydranth body just above the basal whorl of tentacles, 
 producing free medusi' with four radial canals and five superficial meridional orange-colored bands, 
 when fully mature. The single tentacle is greatly enlarged, and near its base a number of medusfc in 
 various stages of development are attached, and these again may in the same manner bear still other 
 groups of inedus.'c. 
 
 Color. The pigmentation of both hydranth anil medusje is orange red. 
 
 Distribution. Deep pools of sea water (Agassiz). The medusa only has teen taken at Woods 
 Hole, being collected in the tow net by Mr. Vina] Kdwards 011 March '2, At that time the or&nge 
 bands were not conspicuous. 
 
 Hydnitheca- and gonangia jir<iseilt. 
 
 Ti-o/i/iiiMiiiti: Hydrothecui wt'H developed, nonojjereulate, either with distinct pedicels or nearly 
 sessile, but not adnate to or partly immersed in stem or branches. Hydrothecal cavity distinctly 
 differentiated from cavity of stem by a septum perforated to allow a co>nosarcal connection between 
 hydranth and pedicel. Hydranth with a tnun])et-shaped or subglobular proboscis. 
 
 (loiioxoiiif. (ionophores either developing the generative products directly or producing medusse 
 which usually have otocysts, and in which the ovaries are situated along the course of the radial 
 canals and sometimes on the prolx>scis also, but never on the proboscis alone. 
 
 Ki'ij tn ijeni'fii nf f'liiit/Hiiinliii'iil.v fiimiil in tlie Wooth Hole region. 
 
 A. Stein iinl n-iiularly Uriiiu'luHl. 
 
 o. Hydrotlu-ca- on IOIIK pedicrls. 
 
 It. Fri-t- nu-'liisit with four imirginal toiitaclL-s nt birth ..... , ................................................. Ctytia. 
 
 1>'. No im-dusji-. Kcprmlnctioii by phinulio ........................................................... CampaHularia. 
 
 n'. Hyirothrcif tubular. Pedivi'ls short. Miirgin o( hydrothocse entirr, not toothtnl .......................... Hebella. 
 
 A'. Stem rcK"larI\- l>ranche*l. 
 
 it. Fr<f ?iH'<tMs;i' \vitli Id or more innrKiual tontacles. Litlmt-ysts on tlu 1 bases of tentacles ..................... Obelia. 
 
 a'. No free mednsf. the mature Konaiimia bearing meilusa-likc sporosncs on their summits ............... Hmmtlujra-ir. 
 
 n". No fro i meilu;e, the planulse being developed within the gonangiura ............................... Campanularia. 
 
 The Onmpanidaridx offer great difficulties in iilentilication, owing to the necessity of basing generic 
 characters on the gonosome and the practical identity of the trophosomes of different genera. The 
 following entirely artificial key, although inadequate in .some cases, is presented to aid the collector 
 and student in the identification of specimens without the gonosome. 
 
44-J lil'U.KTl.N UK THK LIMITED STATES FISH COMMISSION. 
 
 ^ e !l j'urji/eit/ijii-uti'jii </; ' 'ampanutaridte found in Wood* Hole, 'region (based on trophosome alone). 
 
 \. Sloni neither re imlnrly branched nor fascicled. This includes cases where a pedicel supports other pedicels springing 
 
 from it in an irregular manner, 
 u. Pedicels siron.uly tmnulated throughout. 
 
 b. Hydrothecal margin not toothed, but entire Campamitaria, poteritim 
 
 b'. Hydrotheeal margin evidently toothed. 
 
 e. Hydrotheca: small, tubular. Teeth very shallow ClytinvolubUii. 
 
 *'. Tcet h sharp, deeply cut. Hydrotheca: .small, with a tendency to irregular branching. . Campatiularia laznuta. 
 a'. Pedicels not strongly annulated except at ends, 
 l<. Hydrothceal teeth squared off at ends. 
 
 Hydrotheeae ornu mented with vertical 1 incs Campanularia Itiiickiii. 
 
 b'. Hydrothecal teeth evenly rounded. Hydrothecae very large, with parallel sides and exceed- 
 ingly thin walls Clytia yrayi. 
 
 li". Hydrothecal teeth sharply pointed, the extreme tips sometimes rounded. 
 
 c. Pediet-ls usually more than three times the length of hydrothecae. Hydrothecae deeply 
 
 campanulate Clytia bicop/iora. 
 
 !'. i-cdicels seldom more than three times the length of hydrotheca:. 
 
 d. Hydrothec;e broad, often subtriaugular in outline Clytia nolifonais. 
 
 (/'. Hydrothec;e deep, cylindrical '. Clytia cylmdr'uxt. 
 
 A'. Stein regularly branched. 
 ti. Stem fascicled. 
 
 b. Hydrothec;e with pointed or regularly rounded teeth. Pedicels arranged in verticils around 
 
 Mem Campamilaria verticitlata. 
 
 b' . Hydrothecae with very shallow evenly rounded teeth. Colony with subverticillate branches. . Obelia Imiffiesima, 
 b". Hydrothcca? with square, or bimucrunate teeth. 
 
 c. Hydrotheca: ornamented with vertical lines or longitudinal ridges. 
 
 tf. Hydrothecae very deep, tubular. Pedicels with more than (i annulationa Obelia biaiKpid,ata. 
 
 it'. Hydrotheeienot so deep. Pedicels with usually 3 to annulations Obelia bldf.nt.aia. 
 
 f. f . Hydrothecae without evident longitudinal lines ..Obelia gelatinosa. 
 
 a'. Stem not regularly fascicled. 1 
 a. Hydrothecal margin toothed. 
 
 b. Pedicels usually in pairs or subopposite Campanvlaria cdwardei. 
 
 b'. Pedicels regularly alternate. 
 
 c. Pedicels longer than hydrothecae, not completely annulated Campanularia ntgtecto. 
 
 c'. Pedicels shorter than hydrotheca:. 
 
 d. Aperture of hydrothecaa broader than middle part Gonothyrza tenuit. 
 
 d f . Aperture scarcely broader than middle part G&nothyrxa loveni. 
 
 a'. H ydrothecal margin even, not toothed. 
 
 b. Colony with a very slender central stem, from which much-branched short lateral branches 
 arise in a verticillate manner. 
 
 c. Hydrothecse triangular in outline. Pedicels usually with 4 to 6 annulations Obelia flabclfata . 
 
 c'. Hydrotheca! deeper, subtriangular in outline. Pedicels usually with more than 6 annula- 
 tions Obelia eommitturalit. 
 
 r". Hydrotheca: deeply campanulate. Pedicels often considerably longer than hydrothecae, 
 
 and with their middle portions not annulated Campanularia amphora, 
 
 bi. Colony not branched in a regularly verticillate manner. 
 
 r. Stem nearly straight, branches strong, suberect, and giving off bushy branchlets. Hydro- 
 
 i In <;!: very deep, campanulate. Pedicels very short Obelia dicfiotonia. 
 
 c'. Stem strongly flcxuose. or geniculate, usually not profusely branched, and giving off alter- 
 nate pedicels. 
 '/. Stem flcxuose. Hydrotheeae deep, with slightly everted margins. Pedicels sometimes 
 
 quite long, with middle portions not annulated Campawflaria valccolifcra. 
 
 <r. Stem decidedly flexuose, each pedicel forming a graceful curve continuous with the 
 intornode from which it springs. Hydrothecae campanulate. Pedicels with ti to 
 
 12 annulations Otmpannlaria fictuosa. 
 
 <l". Stem gcniculate, or abruptly bent at the nodes. 
 
 r. Pedicels long, with many annulations Campamilaria anfiulaia. 
 
 r'. PediceN short, borne on broad processes from stem. Hydrothecas subtriangular. . . Obdia i/c 
 ,\". Colony parasitic, usually growing iti a straggling or irregular manner over other hydroidH. Hydrothecie 
 
 tubular, with even margins. Pedicels very short, sometimes hardly apparent.. (Genus 
 n. Hydrothec:c large, curved. Colony almost always found growing symmetrically over ,^ci-ttilaria 
 
 rnrn iff/in ffebella catcarata. 
 
 ', Hydrothecu' much smaller. Colony growing in a straggling manner over various hydroids and 
 
 other organisms Il'brtla pitfiiii.rfi. 
 
 1 An appearance "i liiM'ieiilationis often produced when a simple stem is overgrown with parasitic hydroids, oruveii 
 when young colonies are growing over oldw ones of the same fpccies. 
 
ItlDKolHS (>K Till-: WOODS llol, |.; UK.u lo.\. 
 
 Ci.YTIA. 
 
 Trophn/wme. Colony not regularly branched. Hydrothecio with toothed margins and long 
 pedicels. 
 
 (lononome. Gonangia containing goimphorcs which produce medusa- with 4 radial canals, 4 
 marginal tentacles at birth, and 8 lithocysts between the tentacle bases. 
 
 Key to the specie* of t'li/l in fnniiil in Ilir Womh I Me re.ifion. 
 
 Hydrotlioffp small, bell-shaped, with doc-ply rut ti-c-lh ('. bici/iiliora. 
 
 Hydrothee;e small, eylindrical, \vi(h sharp teeth and short pedicels <'. fi/liii'lrtrn^ 
 
 Hydrothectc larger, stout, broadly onmpaiuilate, or subtrianifiilar in outline, 
 
 With large, evenly rounded tooth f. inilifiinnis. 
 
 very lai'K*'. \vilh parallel sides and evenly rounded teeth t\ tj\-<t>:> . 
 
 Clytia bicophora Ag. Fig. 21. 
 (Cont. Xat. Hist. U. S., iv, p. 304.) 
 
 Trophoxome. Stem seldom branching, never regularly so. Hydrothecic 
 deeply campanulate, with about 14 pointed teeth. Pedicels large, long, annulated 
 at the ends, usual!}' smooth through the middle portion. 
 
 Gonosome. Gonangia deeply and evenly ringed, resembling a Chinese lan- 
 tern, usually borne on the root stock, sometimes, on the stem. Medusa whpi 
 liberated hemispherical, with 4 tentacles and 8 lithocysts situated between the 
 bases of the tentacles, and a short manubrium. 
 
 Distribution. Shallow water, attached to shells, other hydroids, seaweed, 
 etc. Found on the stems of Tubularin crocea growing on the piles of the U. S. 
 Fish Commission dock at Woods Hole. 
 
 Both llincks and Verrill regard this species as identical with f'ltjtin john- 
 
 sloni Alder, of British waters. I have carefully compared American specimens o^ 
 
 ( '. liimjiliom with specimens of C. johnsloni from England, and find that the former 
 
 is a much more delicate and smaller species, the hydrothecse of C. johiifloni being 
 
 on the average twice as long and wide as those of C. bicophoru. 
 
 Clytia cyliudrica Ag. 
 (Cont. Xnt. Hist. r. S., iv, p. 306.) 
 
 Trophosome. Stems unbranched, with pedicels shorter than 
 in C bicophoru, annulated at the proximal and distal ends. H ydro- 
 
 thecfe cylindrical, small, deep, with about 10 deeply cut, sharply 
 i.'. t -V. ,, 21. ClijtiabicoplioraAg. 
 
 painted teeth. 
 
 <;<i/io*ome. Gonangia slender, oblong, flattened, not annulated, containing devel- 
 oping medusas which escape singly. Medusae not described. 
 
 Distribution. Much as in the last species. Found in Buzzards Bay and at Xauahon. 
 (A. Agassiz.) 
 
 I have not seen this species, and have compiled the above dscriptions from the 
 writings of Louis and Alexander Agassiz. 
 
 2-2. ciiilia noli- 
 formis 
 
 Clytia noliformis (McCr,). Fig. 22. 
 (Campanularia naliformis McCr., Proc. Elliott Soc., vol. I, No. 1, . 194.) 
 
 Trophnnome. Pedicels short, unusually not more than twice as long as the hydrothecte, strongly 
 annulated, rising from a creeping rootstock. Hydrotheae broadly campanulate, with 10 to 12 very 
 prominent, deeply cut teeth with rounded points. Texture of hydrothecfe stater than in other 
 species of the genus. 
 
 Gonomme. My specimens are without gonangia, and' I have been unable to find an^ description 
 of them. 
 
 It is not certain that this species occurs in the Woods' Hole region. Dr. Agassiz reports it from 
 Buzzards Bay, but as he considers it identical with the ('///tin c/i/iiiili-irii of his father's work, a species 
 that appears to me to be distinct, I am not sure whether he had McCrady's species or not. My own 
 specimens came from Beaufort, N. C. 
 
344 
 
 01 THi: I .\tTKI) .VL'ATKS Kl.SH OiM.MlSSloN. 
 
 Clytia grayi, new species. Fig. 23. 
 IVop/iosom?. Stems unbranched or irregularly branched, strongly annulated, except on middle 
 
 portion. Hydrothecse very large 
 
 23. Clytia ffrai/i Nutting. 
 
 A. Hydrotheca with hydranth (enlarged ) . 
 
 (twice as large as in C. Ijirrijthoru), cylindrical, the sides being 
 parallel and bottom hemispherical; marginal teeth about 16 in 
 number, evenly rounded and not very deeply cut. There is often 
 a tendency to a longitudinal plaiting, which shows as short, 
 straight lines running downward from between the teeth. Hy- 
 dranth with about 20 tentacles. 
 
 Gonosome. Gonangia oblong, conspicuously and regularly 
 annulated, attached to creeping rootstock. Medusae not known. 
 
 Distribution. Found growing on living worm tubes com- 
 posed of sand. Dredged by the Fixh Hawk at station 7051, lati- 
 tude, 40 46' 30" N. ; longitude, 70 40 / W. Depth 31 fathoms. 
 
 The largest Clytia yet found in American waters. 
 
 Named in honor of Mr. George Gray, of the Marine Biolog- 
 ical Laboratory at Woods Hole, a man who has done much for 
 American marine biology. 
 
 CAMPANTJLARIA. 
 
 TrophosomeS Colony unbranched, regularly branched, or 
 fascicled. Hydrotheca;, without operculum and with or without 
 marginal teeth. 
 
 Gonosome. Gonangia producing sexual products which de- 
 velop into planuln; within gonangium. No medusre. 
 
 K?u in species of Campanularia foimd in the Woody Hole region. 
 
 A. Colony not regularly branched. 
 
 a. Hydrothecre with margin entire C. potcrium. 
 
 a'. Hydrothecal margin toothed. 
 
 6. Teeth square or truncated at top C. hincksii. 
 
 b'. Teeth very shallow, formingsinuositiesornndnlationsaroundaperture. Hydrothecae deep, tubular. .C. volubilit, 
 
 b". Teeth very sharp and deeply cut, pedicels long, stem irregularly branched C. miniita. 
 
 A'. Colony regularly branched. 
 a. Hydrothecal margin toothed. 
 
 6. Teeth castellated or bimucronate C. negteeta, 
 
 b'. Teeth acute, stem not fascicled c. edwardsi- 
 
 b". Teeth sharp or rounded, stem fascicled c. vcrtfiillntQ. 
 
 a. Hydrothecal margin entire. 
 
 b. Branches arranged in subverticillate manner around a slender axial stem. Pedicels often 
 
 longer than hydrothecce C. amphora. 
 
 b'. Branches not arranged in a subverticillate manner. Main stem giving off alternate pedicels. 
 
 c. Stem angulated, or strongly geniculate. Pedicels long C. angulata. 
 
 c'. Stem flexuose. Pedicels annulated throughout. Gonangia with a large terminal aperture C. flrmosa. 
 
 c". Stem slightly flexuose. Pedicels long, not always annulated throughout. Gonangia with 
 
 a subterminal aperture C. calc?ol(fe>'tt 
 
 Campanularia poterium (Ag. ). Fig. 24. 
 (Cont. Nat. Hist. U. S., p. 297.) 
 
 Troplwsome. Stem unbranched, the pedicels arising directly from annulated rootstock; pedicels 
 annulate throughout, the annulations often oblique, giving a twisted appearance. Hydrothecre 
 deeply campanulate; aperature not toothed; basal portion thickened greatly, so as to include what 
 appears to be the uppermost annulation. Hydranths with 24 tentacles. 
 
 Gonosome. Gonangia rather slender, not decidedly annulated, growing from the rootatock. The 
 sexual products pass through part of their development in an acrocyst resting on top of gonangium. 
 
 i It appears to be impossible to construct generic characters for the Campanularldy, on the basis of the trophosomes. 
 The classification of the group is unnatural and unsatisfactory in the extreme, but this is not the place to attempt its 
 rectification. 
 
HYDROIDS OF THE WOODS HOLE REGION. 
 
 345 
 
 Distribution. Found growing on stones, shells, seaweed, etc. A specimen in the U. S. Fish 
 
 Commission collection is labeled: "Off Nantucket Island." Depth, 23 fathoms. 
 
 Campanularia hincksii Alder. Fig. 25. 
 
 (North, and Durh. Cat. in Trans. Tyneside Field Club, III, p. 127.) 
 
 Tropliomme. Pedicels springing directly from a creeping rootstock, not extensively annulated. 
 Hydrotheca? large, deep, cylindrical, With about 12 prominent square-topped teeth, from between 
 which vertical lines pass dtown over the surface of the hydrotheca. 
 
 Ganosome. Gonangia long, annulated, resembling that of Clyiiajohnstoni, but often not so deeply 
 annulated. 
 
 Distribution. Growing on stones, shells, etc., in rather deep water. A specimen was secured 
 from a depth of 15 fathoms near Newport, R. I. Contrary to the rule among campanularians, the 
 hydranth of this specimen was brilliantly colored, the general color being yellow and the basal part 
 scarlet. 
 
 Ctomp<mulaFfa poterium ( 
 
 fi. 
 
 J.V <'ttiiii>fii>nlftt'/(i fiiiu~'knfi Alder. 
 
 A. Upper part of hydrotheca (enlarged). 
 
 26. Campanularia volubilis (Linn.). 
 A. Hydrotheca (enlarged). 
 
 Campanularia volubilis (Linn.). Fig. 26. 
 (Syst. Xnt., p. 1311, under name of Sertularia mlubilis.) 
 
 Tropliosomc. Pedicels long, extensively annulated, springing from a creeping rootstock. Hydro- 
 thecse small, tubular, with about 10 shallow rounded marginal teeth. 
 
 Ci,tioitomf. Gonagia borne on the rootstock, flask-shaped, with a long tubular neck and small 
 terminal aperture. 
 
 Distribution. Found growing on Sertularetta trienspidata on specimens in the U. S. Fish Commis- 
 sion collection; supposed to be from rather deep water. 
 
 The combination of tubular hydrotheoe with very shallow teeth and extensively annulated 
 pedicels will differentiate this form from others on the North Atlantic coast. 
 
 Campaimlaria minuta, new species. Fig. 27. 
 
 Trophosoms. Stem branching in an irregular straggling manner, attaining a height of about 
 one-fourth inch. Pedicels long, extensively annulated, rising almost parallel with the main stem, 
 which is itself extensively annulated, although there are smooth portions of considerable extent. 
 Hydrotheca very small, deeply campanulate, with 8 to 10 very acute and prominent teeth. 
 
 Gonomme Not known. 
 
 Distribution. Parasitic on Obelia commistnrab's from the piles of the wharf at New Bedford. 
 Collected by Mr. Vinal Edwards. 
 
 This species appears to be quite distinct. It seems to be nearest to C. raridentata Alder, from 
 which it differs in being branched, in the extent of annulations of the pedicels, and in 'the hydrothecse 
 being considerably broader in proportion to their length. 
 
846 
 
 I! I 1.LET1N OF THE UNITED STATES FISH COMMISSION. 
 
 Campanularia edwardsi, neu ^pi ( ii-. Fig. 28. 
 
 Colony attaining a height of over an inch, branching somewhat irregularly, but with 
 a distinct tendency to send off pedicels from the main stem in subopposite pairs. Stems, branches, 
 and pedicels exceedingly long and slender, with the annulations confined to the proximal portions, 
 except a few just below the hydrothecse. Hydrothecse very large, deeply campanulate,.with 12 to 14 
 exceedingly sharp, slender teeth, more acuminate than hrany other species in the region. Hydranth 
 with about 28 tentacles. 
 
 i'. Unknown. 
 
 . The type specimen was found on the piles of the U. S. F..C. dock at Woods Hole. 
 This is one of the most distinct and beautiful of the American campanularians. 
 Named for of Mr.-Vinal Kd wards, the veteran collector at the U. S. F. C. station at Woods Hole. 
 
 '27. {'"iniinii/ilaria mniiita Nutting: 
 A. ami U. Hydrutheca; (enlarged). 
 
 28. Cam fin nturiti rttirnrrl*! Nutting. A. Colony, natural sic. 
 
 Oampanularia neglecta (Alder.). Fig. 2& 
 1 North, and Durham Cat. in Trans. Tyneside Field-Club, p. 123.) 
 
 '. Colony branching, main stem flexuose, giving off alternate pedicels which are long, 
 slender, and annulated at the ends. Hydrotheoe deeply campanulate, almost tubular, with their 
 margins armed with 8 to 10 teeth which are bimucronate; that is, the summit of each tooth is crowned 
 with two minute denticles. 
 
 Gonosome. Gonangia borne in the axils of the pedicels, oblong ovate, smooth, somewhat truncated 
 above. The mature gonangium often has a globular acrocyst on its summit. 
 
 Distribution. la shallow water, on stones, shells, and other hydroids. Reported by Professor 
 Verrill from Casco Bay, Maine. I find it in my notes as occurring at Woods Hole, but fail to find 
 specimens. The figure is from a British specimen. 
 
HVDRO1DS 
 
 TUI-: u'u<>us tuu.K ui-:;i"\ 
 
 Campanularia verticillata (Linn.) Fig. : >0. 
 
 i a I'ti'/Hi-iit n'rtieillnln Linn.. ?}Nt. Nat., p ; 1310.)' 
 
 Ti-<>iili'i*iiitii'. Colony branched, attaining a height of about 5 inches. Stem ami branches fascicled, 
 composed of many parallel tubes from which the pedicels arise in a verticillate manner. Hydrothecse 
 large, rather broadly campanulate, with about 12 deeply cut acuminate teeth. 
 
 29. C<iinii<iiit'!u/'<<t i)fj!"-ta (Alder). 30. Caiujxiniilai-ia rcrticillata (Linn!). 31. Campanularia amphora. (Ag .). 
 
 (iiinoxonif. Gonangia borne on the main stem and branches, oblong flask-shaped, with nefcka 
 produced into tubular extensions with terminal openings. 
 
 Distribution. Found in rather deep water attached to stones, shells, etc., Block Island Round, 17 
 to/ 45 fathoms; Fisher Island Sound, 4 to 11 fathoms. 
 (Ten-ill.) 
 
 Campanularia amphora (Ag. ). Fig. 31. 
 ' Limmnlin amphora. Ag., Cont. Nat. Hist. U. S., iv, p. 311.) 
 
 Trophomme. Colony attaining a height of 6 to 
 7 inches, branching in a subverticillate manner; the 
 branches incline upward more than in Obelia comims- 
 suratix, which it greatly resembles. "But the moist 
 marked difference is in the middle of each internode, 
 where'it bulges laterally and directly in line with the 
 point of insertion of the branch or pedicel below it." 
 (Li, Agassiz.) Pedicels annulated. Hydrothecse deeply 
 campanulate, very gracefully formed, aperture entire, 
 margin slightly everted. Hydranth with about 30 
 tentacles. 
 
 Oonotome. Female gonangia elongate oval, about 
 four times as longas the hydrotheca, somewhat truncate 
 at top, and with a very small aperture. Male gonangia 
 more slender, with a slightly produced neck. 
 
 nixtrilmtion. Common in shallow water in the 
 Woofts Hole region. This specifes is apt to be mistaken for Obelia commisguralw when the gonosome 
 is absent. 
 
 Campanularia angulata Hincks. Fig. 32. 
 1 (Annals and Magazine of Nat. Hist,'; 3d series, vm, p. 2C1.) 
 
 fmphonome. Colony slightly branched, attaining" a height of about three-fourths inch. Stem 
 genitulate, with long internodes, annnlotcd above t.Hi origin of each pedicel. Pedicels long, usually 
 
 32. Campanulafia angulata Kincks. 
 A. Hydrotheca rtnd pedicel (enlarged). 
 
848 
 
 Hl'l.I.KTlN !>K THK UNITKI) STATKS FISH COMMISSION. 
 
 annulated throughout. Hydrothecse rather deeply campanulate, aperlure entire, llvilrantli with 
 about 24 very slender tentacles. 
 
 (.JoiiDHonn'. (ionangia borne on the rootstock, irregularly ovate, ob.-ruivly wrinkled, neck short 
 and broad. 
 
 Dixlriliiitiun. f have several fragmentary specimens from Woods Hole region that agree very 
 closely with Mincks's figures. Comparing these, however, with some of the terminal branches of 
 ('. iimjilior/i, I find them to agree closely witli these also. Verrill reports the species from Casco Bay. 
 I do not know whether his material embraced the gonosome or not. 
 
 Campanularia calceolifera llincks. Fig. 33. 
 
 (Annals mid MiiKii/.iiirni' Xui. Hist., Illi series. vol. vill. p. 7S.) 
 
 Trophngtiine. Colony usually consisting of a single slightly flexuose stem, but sometimes it gives 
 off long branches similar in every way to the main stem, which sends off alternate pedicels of varying 
 length, but usually fully annulated and considerably 
 shorter than the hydrothecie. Hydrothecii 1 without 
 teeth, deeply campanulate, and with gracefully everted 
 margins. 
 
 (ioHOKomf. Gonangia of peculiar shape, taper- 
 ing basally, with latero-tcrminal aperture from which 
 a short, curved tube projects into the gnmingial 
 cavity. 
 
 IHxtrllnitliiii. In shallow water on stones, sea- 
 weed, submerged timbers, etc. Noank, Conn., on 
 
 33. Oliiiiiniiiilnriii nilmilifcra Hincks. 
 
 34. Camiianulariaflemom Hincks. 
 
 A. Gonangium with escaping Phmuln. 
 
 bottom of boat (Clarke). Woods Hole, on piles of U. S. Fish Commission's dock. 
 
 This beautiful species can be immediately identified when sexually mature. Otherwise the best 
 character is the elegant shape of the hydrothecw. 
 
 Campanularia fiexuosa (Hincks). Fig. 34. 
 (Annals and Magazine of Nat. Hist., 3d series, vol. vm, p. 260. Under name of Laomtdia fiexuosa.) 
 
 Trophosome. Colony usually in the form of a single flexuose stem giving off a series of regularly 
 alternating pedicels. Stem with three or four well-marked annulations above the origin of each pedicel; 
 pedicels apparently continuous with the internodes from which they spring, and with which they curve 
 continuously, rather large, completely annulated and diminishing gradually in size toward the distal 
 end. Hydrothecse campanulate, not very deep, with even rims. Hydranths with a web between the 
 bases of the tentacles. 
 
HYDROID^ OF THE WOODS HOLK KKGHXY. 
 
 349 
 
 (,'itiiiisniii,: Female gonangia very large and abrupt ly tiuticated above; male gonangia much 
 smaller and more oval, but with no neck; sexual products forming planuhe before leaving gonangia. 
 
 Disli'iliiilinii. Very abundant on floating seaweed, and rock* and timbers in shallow water. One of 
 the most abundant species at Woods Hole. 
 
 OBELIA. 
 
 TrnpJioxniiie. Colony branched, stem simple or fascicled. IIydrothec;e campanulate, margin 
 even, or toothed. 
 
 ilniitiMiiiii: Gonangia borne in axils of pedicels, usually oblong ovate, with terminal aperture 
 usually surrounded with a collar or short neck. Mrdus;c with disk-shaped umbrella, 4 radial canals, 
 more than 8 marginal tentacles, 8 lithocysta borne on bases of tentacles, and a short manubrium 
 without mouth tentacles. 
 
 It is apparently impossible to define this genus so that it can be distinguished from 
 by the trophosome alone. 
 
 35. Obeliajlabe/lata Hincks. 
 
 36. Olelia commissuralie McCr. 
 
 Key to the species of Obelia found in the Woods Hole region. 
 
 (A very careful manipulation of the microscope is often necessary before the characters of the 
 hydrothecal margin can be definitely determined. ) 
 
 A. Hydrothecal margin entire. Stem not fascicled. 
 
 a. Colony a long central stem, giving off subverticillate branches which are themselves palmately branched. 
 
 b. Hydrothecse triangular. Pedicels usually with more than 6 annulations 0. fabeUata. 
 
 b'. Hydrothecse deeper, subtriangular. Pedicels often with more than 6 annulations 0, commiwuraJis, 
 
 a'. Colony irregularly branched; branches erect, often themselves branched. Hydrothecse large, very 
 
 deeply campanulate 0. dichotoma. 
 
 a". Colony usually consisting of a single geniculate stem, giving off alternate pedicels which are sup- 
 ported on broad shoulders of the internodes from which they spring O. geniculata. 
 
 A'. Hydrothecal margin toothed. Stem fascicled. 
 a. Teeth bimucronate, or castellated. 
 
 6. Hydrothecse triangular, without vertical lines 0. gelatinosa. 
 
 b'. Hydrothecee deep, ornamented with vertical lines. 
 
 c. Hydrothecse deeply tubular. Pedicels with 6 to 15 annulations 0. bicuspidata. 
 
 c'. Hydrothecse shorter. Pedicels with 3 to 6 annulations 0. bidentata. 
 
 a'. Teeth forming a series of exceedingly shallow undulations around the hydrothecal margin 0. longissima- 
 
350 
 
 Bt T I.I,FTIN OF THK 1 T N T ITED STATES FISH COMMISSION. 
 
 Obelia fiabellata (Hinrks). Fig. :::>. 
 
 iiaiiiilnrMjIiilitllitta Ilincks.. Ann. mid Mag. Nat. Hist., 3.1 MTJI-S. M)l. .win. p. L>'.i7. i 
 
 i'. Colony 8 to 10 inches high, consisting of a central geniculate stem, giving 'forth 
 branches which themselves branch in a tlabellate manner; stem not fascicled, annulated above the 
 origins of the branches. Pedicels borne on rather short processes or shoulders of the branches, 
 distinctly annulated, short. Hydrotheca 1 triangular in outline, margin entire. 
 
 (;niKHime. Gonangia borne in axils of pedicels, oblong ovate, with a terminal collar and large 
 round aperture. Medusa' not described, so far as I can ascertain. 
 
 Dixtribatiriii. Found in rocky tide pools (Hincks). Off Thimble Island, 4 to 5 fathoms. Woods 
 Hole, in the passage (Yen-ill). 
 
 Obelia cornmissuralis McCr. Fig. :!i>. 
 I I'rocw.linirs Klliolt Sor.. vol. i. No. 1, p. 197.) 
 
 Ti'H/'liox'iiiK'. Colony attaining a height of <> to 8 inches, consisting of a central geniculate stem 
 giving off branches as in <>. t/iilu'l/n/n. Pedicels not borne on distinct shoulders of the branches, 
 distinctly annulated. 1 tydrotlicr.-i' cumpamilatc. often snbtriangular, but considerably deeper than 
 in <>. tloliflMii. 
 
 37. Obelia ilirholoma (Linn.). 
 
 3X. Obeliaffeniculata (Linn.). 
 A. Medusa. 
 
 39. Obelia gekttiuota (Pallas). 
 
 A. Portion of fascicled stem (enlarged), 
 
 (iviiofome. Gonangia much as in the last species, but larger and less distinctly ovoid. Medusae 
 at literation with 1(1 marginal tentacles. 
 
 Distribution. Growing profusely on docks and floating timbers. Abundant all along the New 
 England coast. 
 
 The branching is exceedingly elegant and delicate, forming feathery verticillate tracery around 
 the slender central stem. 
 
 Obelia dichotoma (Linn.). Fig. 37. 
 (Scrtularia rlichotoma Linn., Syst. Nat., p. 1312.) 
 
 Ti-ophosome. Colony branching irregularly, the branches tending to assume an erect posture, 
 not subverticillate. Pedicels short, usually with 4 to 6 annulations, but sometimes with many. 
 Hydrotheoe large, deeply campanulate, with straight sides and no teeth. 
 
 Gonosome. Gonangia long, slender, widening toward distal end, and terminating in a beveled 
 collar. Medusae at liberation with 16 marginal tentacles. 
 
 Distribution. Rather shallow water. Off Gay Head, 8 to 10 fathoms. (Verrill.) 
 
 I suspect that this is the same species as Eucope pyriformis A. Ag., but, not having seen his types, 
 I can not be certain. 
 
HYDKOIDS OF THE WOODS HOLE REGION. 
 
 351 
 
 Obelia geniculata (Linn. ). = A'mv>yje diaphana L. Ag. (in part ).=.Eucope alternate A. Ag. Fig. 38. 
 
 (Sertularia geniculata Linn., Syst. Nat., p. 1312.) 
 
 'rm/ihoKimii', Colony usually consisting of a single geniculate stem bearing alternate pedicels on 
 broad shoulder-like processes. Pedicels short, usually with 4 to 6 annulations. Hydrothecte short, 
 campanulate or subtriangular. 
 
 llonosoine. Gonangia long, tapering gradually to basal end and terminating in a collar which is 
 beveled and convex on its surface. Medusa; at liberation disk-shaped, with 24 marginal tentacles. 
 
 Dixtriliiitifiii. Growing profusely on docks, floating seaweed, etc. One of the commonest species 
 in the Woods Hole region. 
 
 Obelia gelatinosa (Pallas). = Lumnnlw g-igantea A. Ag. (ti'xte Verrill). Fig. 39. 
 (Sertutaria yelatiuosa Pallas, Elenchus Zoophytorum, p. 11C.) 
 
 Troptiosome. Colony sometimes attaining a height of 15 to 20 inches, profusely branched in a 
 dendritic manner. Stem fascicled, with geniculate branches. Pedicels usually quite short, with 3 to 5. 
 annulations. Hydrotheae small, campanulate or sub- 
 triangular; margins armed with castellated or bimu- 
 cronate teeth. 
 
 Gonoaome. Gonangia rather small, ovate, with 
 collared aperture. Medusas with 16 tentacles at time 
 of liberation (Hincks). 
 
 Distribution. Shallow water, of ten bet weei 1 1 i d ( >w , 
 attached to timbers, etc. New Haven. Rhode Island 
 coast. Vineyard Sound. 
 
 Obelia bicuspidata Clark. Fig. 40. 
 (Trans. Conn. Acad. of Sci., ill, p. 58. ) 
 
 Trophosomr. Colony attaining a height of 
 about 33 inches. Stem fascicled, straight, irregu- 
 larly branched. Pedicels longer than in the next 
 species, and with 10 to 15 annulations. Hydrothecae 
 very deep, tubular, -their margins armed with bimu- 
 cronate teeth, between which lines originate which 
 pass down the surface of the hydrotheca:. 
 
 Gonoxome. Unknown. 
 
 Diitril>iiti<M.owd at a depth of 3 to 5 fathoms, from reefs near Thimble Island. Near Woods 
 Hole, 19 fathoms. 
 
 Obelia longissima (Pallas).. Fig. 41. 
 (fSertularia hmgiiasiina Pallas, Elenchus Zoophytorum, p. 119.) 
 
 Tmjilioxoiiie. Colony attaining a height of 12 to 14 inches. Main stem fascicled, flexuose, giving 
 off branches, which themselves branch in a palmate manner, the whole thus being subverticillate in 
 effect. Pedicels of varying length, usually extensively annulated. Hydrotherae rather deep, cam- 
 panulate, the margins appearing at first sight to be without teeth, but upon careful examination 
 proving to be armed with very shallow, regularly undulating teeth. 
 
 Gonosfime. Gonangia ovate, with collared apertures. Medusa; at the time of liberation with 20 
 to 24 tentacles (Hincks). 
 
 Distribution. Woods Hole. Off Gay Head. Dredged by the Fish Hawk at station 7051, about 40 
 miles southeast of No Mans Land ; depth, 3 fathoms. 
 
 As described by Hincks, this species has not a fascicled stem. Authentic specimens from England, 
 however, have distinctly fascicled stems, and agree well with American specimens. 
 
 Obelia bidentata Clark. 
 (Trans. Conn. Acad. of Sci., m. p. 58.) , 
 
 Trophosome. Like that of (>. bizcuspidata, except that it attains a larger size, has shorter pedicels, 
 with 4 to .6 annulations, and proportionately wider hydrotheca?. 
 
 40. Obelia bicuspidata 
 Clark. 
 
 41. Obelia Ivngissimn Pallas. 
 A. Outline of ap orture of 
 hydrotheca. 
 
352 
 
 BULLETIN OF THK ITNITKI) STATF-S FISH COMMISSION. 
 
 e. Unknown. 
 
 it. On piles, Greenport, Rhode Island. 
 I have a specimen that to a certain extent intergradcv between this species ami the preceding, 
 and therefore suspect that the two species may be identical. 
 
 (iOXOTHYRjEA. 
 
 Trii/'liimiiiit'. Stem not fascicled, branched. Hydrothecse campanulate, with toothed margins. 
 
 OtmOfOme. The gonaugia producfcto fixed, medusil'on.i sporosacs with apical filiform tentacles. 
 The spornsacs, \\lien nearly mature, pass out of the 
 gonangiiim and remain attached to its top until the 
 spermato/oa or planulie are discharged. 
 
 Gonothyrsea loveni Alhnan. Fig. 42. 
 
 (Ann. mid Mas;, of Xat. Hist., 3d scries, vol. 13, p. 374.) 
 
 ie. Stem irregularly branched, attain- 
 ing a height of one-half to three-fourths inch, slightly 
 flexuose, annnlated above origins of pedicels. Pedi- 
 cels short, with 2 to 5 annulations. Hydrothec.-e 
 deeply campanula!?, gracefully tapering toward base> 
 very thin and transparent aronnd margin, which is 
 quite variable in its dentition, the typical teeth being 
 turreted and squared at the ends. 
 
 Gotuisumi'. (ionangia large, long, obconic, borne 
 in the axils of the pedicels, each bearing, when ma- 
 ture, :> to 5 sporosaes or modified medusa 1 on its sum- 
 mit. The sporosacs are attached to the top of the 
 gonangium by short pedicels, and have at their upper 
 end acirclet of short tentacles. They discharge their 
 contents before becoming free. 
 
 I>irti-ilinti(iii. On shells, stones, etc., in shallow- 
 water. Dr. II. C. Bumpus sent the writer some beau- 
 tiful specimens from the coast of Rhode Island. 
 
 Goi><>tliiii-:m ifnuix Clark, fig. 43, is reported from New Haven. There is no point either in the 
 original description or in the figure published by Dr. Clark that enables me to separate this species 
 from typical specimens of <:. lnn-ni from England. Professor Yen-ill says of this species: "Closely 
 allied to (1. lumii, but has narrow, elongated, obconic gonotheca;." As these terms are precisely appli- 
 cable to the gonangia of (j. loveni, I can not perceive any basis for considering (.!. li'unix a good species. 
 
 GonotJiynra Injalina Hincks is also reported by Professor Verrill as occurring off Watch Hill, 
 Rhode Island. The writer, while at Plymouth, England, found completely intergrading specimens 
 between this species and < S. lun-ni. 
 
 HEBELLA (modified). 
 
 4^. (iiiiiofhifl T :i'it J 
 
 . <;<nxiUii/r;fit tcn/ii* Clark- 
 
 iiiiii: Pedicels arising from a creeping rootstock. llvdrothecic tubular, with entire 
 margins and without opercute. Ilydrothecal cavity separate'! from that of the pedicel by a partial 
 septum. 1 1 yd ran th with a conical proboscis. 
 
 (,'tiiiiisniiir. (ionangia producing t'r. : 'e medus.'e. 
 
 The genns as here defined would include several species which most authors place in the genus 
 
 Kei/ in s/ierii'x <>f Hi'lirllii fimiiil in tin 1 \}'iuiijs lln'.i' ri'i/iini. 
 
 issiiitlly in pnirs. ilnulily curved. Species ulini'-t always nar.-isitic on ('//'/-ic/'a <<>,- u'fniti ..... II. ralcatata. 
 HydrotlH'Cit irregularly distribuled. small, nut douMy curvc'l. Sprric< p:'.r:i-itie mi \iirious hydrnids ...... //. vj'/'"/' "(. 
 

HVDKUIDS OF THK U'UOI^ HO1.K KKUtoX. 
 
 Hebella calcarata (A. Ag. ). Fig. 5ii. 
 
 (iMj'u-n mli'iimltt A. \f.. North Anierieun Aealepliie. p. 1!.) 
 
 Tm/ihosome. Colony parasitic, almost always on ,S'.rMA,v/</ oormctno, where il assumes a sym- 
 metrical mode of growth, the' main stem growing straight up the front of the host and giving forth a 
 pair of hydrothecie immediately above each pair of the sertularian hydrothecie. Pedicels very short 
 and slender. Hydrothecie large, curved outward, backward and upward; margin circular, entire. 
 Hydranth with a conical hypostnme am! about 16 tentacles. 
 
 diiiiumiiii'. (ionangia very large, borne on pedicels between the pairs of hydrothecse. Medusc 
 at liirth deeply campanulate, with two long marginal tentacles, and others in course of development; 
 4 radial canals and yellow-spotted proboscis. 
 
 Dixh'iliiitidii. Found attached to '/jmli'm at \Voods Hole by Mr. Walmsley. Vineyard Sound, 
 1 to 8 fathoms (Verrill). 
 
 This species was originally described by McCrady aa a part of the sertularian OH which it grows 
 
 Hebella pygmaea (Alder) MS. Fig. 44. 
 
 (See British Hydroid Zoophytes, p. -J05.) 
 
 Trophotome, Pedicels springing direct from a simple creeping rootstoek, very 
 short, annulated. Hydrothecie minute, cylindrical, deep; aperture smooth, sometimes 
 somewhat oblique, as in figure. 
 
 Ghmotonte. Unknown. 
 
 l>ixli-iliiiti/>ii. Found on a polyxoon off Nant ticket; Sankety Light east by south, 
 24 fathoms; depth, 24 fathoms. (Vinal I'M wards.) 44. iirbel/n pyg- 
 
 This minute species is identified with considerable doubt. m*a (Alder). 
 
 J'- ' ' T 
 
 CAMPANULINIDiE (modilied). 
 
 omi'. Colonies branched or unbranched. Hydrothecre borne on pedicels, tubular, ending 
 in an operculum composed of converging segments. Hydranths with a conical proboscis. 
 tiniiiixdiiu'. Gonangia producing planulsp, or free medns,-e. 
 This family is here modified to include the 
 genera Loreiiellu and Cnlijivlln, the former having 
 heretofore been placed in the Crimpanularid.r. and 
 the latter in the Lafaid.r. Both agree with the 
 genus ('(impinin/iiHi in having hydrothecse with a 
 segmented operculum and hydranths with a conical . 
 proboscis. 
 
 Key to rjenem of I 'niiipiinnliii '>;<' nf ]Vuin! IMe. region. 
 
 A. Colony usually branched. 
 
 a. Hydrotheeffi large, subcylindricnl, with 
 
 a \rell-detined sinuous margin 
 
 at base of segmented operculum iMrctniln- 
 
 a'. Hydrothecie much smaller, ovate in 
 
 outline, the margin passing in 
 
 sensibly into the segments of 
 
 operculum CalijrcUu 
 
 A'. Colony not regularly branchcfl. Hydro- 
 
 theciu not wssile tubuliir. often 
 
 with reduplicated miirgins Oiirmtliirrlla- 
 
 A". Colony not branched. Hydrothec* sessile, 
 
 tubular Cniii<lrlln- 
 
 LOVENELLA. 
 
 Ti-o/ihomme. Colony branched. Hydrothecie 
 deep, with a distinct sinuous margin crowned with 
 operculum composed of several triangular segments 
 which form a pointed covering to hydrotheca. 
 
 f ;<,.,. Gonangia borne on the stems and producing free. Mi-shaped medusjp. with S tenta- 
 cles in two sets, and 4 lithocysts. 
 
 F. C. B. 1899- 
 
354 
 
 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 Lovenella grandis, new species. Fig. 45. 
 
 TrophoKome. Stem simple, giving off regularly alternating, short, annulated pedicel?, one from 
 each internode. Hydrothecic very large, cylindrical; margin with 10 regular sinuations from which 
 arise the 10 sharply pointed segments of the operculum. Hydranths large, with a conical proboscis 
 which becomes dome-shaped on retraction, and about 16 rather rigid tentacles. 
 
 t, ',,/, i.i/i, ix'. Not known. 
 
 IHxtrilivtiiiii. Dredged from Newport Harbor, off Castle Hill. 
 
 This beautiful species was given me for description by Mrs. Virginia Barrett Gibbs, of Newport. 
 
 OPEBCDLABELLA. 
 
 Trnfthnanrnf. Stem annulated throughout, Hydrotheea? ovate in outline, the margin not distinct, 
 the segments of the operculum appearing to be very thin and greatly elongated marginal teeth which 
 converge /o form the operculum. 
 
 tiiiiiosiii/it'. The mature gonangia bear acrocysts. 
 
 Keij in n/n'fi,'.i nf Opercutareila found in the W/iuiI.t Jlu/e region. 
 
 Hydrotheca; larger, with more deeply cleft segments of the opercula 0. laceraia. 
 
 Hydrotheeoj smaller, with less deeply ck'ft segments of (he opercula O.pumUa. 
 
 in. <>i ri'iilnrflln liien-ntn Hineks. 
 
 IT. f'nii/iTllii syringa (Linn.). A. Hydrotheea (enlarged). 
 
 Opercularella lacerata Hineks. Fig. 46. 
 (British Hydroid Zoophytes, p. 194.) 
 
 Trophoiomf. Stem annulated throughout, sparsely branched, or unbranched. Hydrothecse with 
 short pedicels, oblong ovate in outline; opercular segments 8 to 10, very long and slender, somewhat 
 curved. Hydranth with conical proboscis and about 16 tentacles. 
 
 Gonomme. Gonangia large, ovate, borne on ringed pedicels, and, when mature, bearing globular 
 acrocysts on their summits. 
 
 Distribution. New Haven, Conn., on piles of Long Wharf. (Clark.) 
 
 Opercularella pumila Clark. 
 (Trans. Conn. Acad., vol. in, p. 61.) 
 
 Like 0. 1/icerata, but with smaller hydrothecfe, and less deeply cleft segments of the operculum. 
 
 In comparing Dr. Clark's description and figure with sketches of 0. lacerata made by myself in 
 England I have serious doubts as to the validity of the former species, but consider it best to let it 
 stand here, as I have not seen the type specimens. 
 
iivi)i:<Tii>- OB TIM: \voons HOLE RICO [ON. 355 
 
 CALYCELLA. 
 
 i'. Stem n ('reeling root-stock parasitic on other species of hydroids, polyzoons, etc., 
 sending forth short annulated pedicels bearing tubular hyln>tlier;e with distinct, segmented opercula, 
 flonoxonii: (ii.MuiMj.tia oval, borne on the root-stock, and, when mature, bearing globular acrocysts. 
 
 Calycella syringa (Linn.). Fig. 47. 
 (Sertiil'trit xi/rinifii I, inn., SyM. Xat., p. 1311.) 
 
 Tro/ihofiniii'. Pedicels shorter than hydrothecse, very deeply annulated. Hydrothecse tubular, 
 with thick horn -colored walls and slightly sinuated margins; opercular segments rather short, triangular, 
 and capable of being drawn into the hydrotheca when the hydranth is retracted. There is often a sort 
 of an addition or tubular extension beyond the end of the hydrotheca, with a distinct margin bearing 
 the opercular segments. 
 
 (liiiitisoini'. (ionangia oval, borne on short annulated pedicels and, when mature, with globular 
 acrocysts. 
 
 Dixlrilmtiini. Found abundantly in the Woods Hole region, growing over all sorts of plant-like 
 marine organisms, especially other hydroids. 
 
 CUSPIDELLA. 
 
 Trophttixnne. Hydrotheca? sessile with a conical operculum. Hydranths with a conical hypostorne. 
 (liinnsdiiie. Not known. 
 
 Cuspidella costata Ilineks. 
 
 (British Hydrnid Zoophytes, p. 210.) 
 
 Troidioxoiite. Ilydrotheere perfectly cylindrical and sessile, encircled with usually three sharply 
 defined annulations dividing the hydrotheca externally into four zones; operculum composed of 
 numerous segments, the distal ends of which can be retracted within the hydrotheca. 
 
 Qtmotome. Unknown. 
 
 Distribution. Reported by Professor Verril! from Fisher Island Sound, 9 to 11 fathoms. 
 
 This species is identified with doubt by Verrill. 
 
 LAFCEIDjE (modified). 
 
 The modification consists of the removal of the small monosiphonic species, such as Lafcea 
 pocillum, which I have placed in Allman's genus Helidlu, and the genus Cnlycetta, which I have placed 
 in the family ('ampniiii/iiiid.r. 
 
 Trnphosome. Stem fascicled. Hydrothecse tubular, without a partial septum dividing the 
 hydrotheca] cavity from that of the pedicel; margin without teeth or opercula. Hydranths with a 
 conical proboscis. 
 
 (roiiosotiti: Gonangia found in compact masses incrusting the fascicled stem, oblong, each female 
 gonangium containing a single ovum. The gonosome of fjafcen was long regarded as a distinct 
 hydroid organism under the name Cup/tlnin n,-r/,i.> 
 
 LAFCEA. 
 
 This being the only genus of /,/i/ //,r found on the New England coast, it can be identified by the 
 family characters as given above. 
 
 Kl'jl In t/ii'xiH'fii'x i if Ldfii'il full ml in tin' ]\'oodit Hull' nyioil. 
 
 ttydrothecse short, almost scssik 1 L. fhiu/"vn. 
 
 Hydrothi-ca- sk-nder, with distinct podicels which are waved or twisted /,. tirai'ilHinn. 
 
 Lafoea dumosa Fleiri'ig. Fig. 48. 
 
 H'hil. .Tonrn., n, p. 83.) 
 
 Trophosotne, Stem simple, in the form of a creeping root-stock, or compound and erect. Hydro- 
 thecit strong, large, tubular, with short, sometimes hardly evident, pedicels. 
 
 1 Srr New Hydroids from Alaska i\ud Puget .Sound, C. 0. Nutting. I'roc. U. s. N. M., vol. xxi, p. 747. 
 
356 
 
 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 Qonowme. < lonangia in musses, im-rusting the fascicled stem, so closely crowded as to be pressed 
 together, tubular or oblong oval with short bottle-shaped necks. Both sexes found in the same colony. 
 tiuii. Found growing on other hydroids on Nantucket Shoals. (Verrill.) 
 
 Lafoea gracillima (Alder.) Fig. 49. 
 i : tnfonularta graeOKma, <';it. /,<">i>]i. Xorthumb. mid Durluim, p. 39.) 
 
 f. Stem erect, fascicled, often irregularly branched. Pedicels slender, sinuous or 
 apparently twisted. Hydrotheoe very slender, delicate in texture, often slightly curved. 
 
 < iiiiii'snini'. Much like that of L. tltn<>.*i<, and heretofore known as Coppin'm <n-r/n. 
 
 l>ixti i !liiit!ti)i. Reported from the Xew England coast by Professor Verrill. Although not 
 specifically reported from the \Vonds Hole region, it doubtless occurs there, as its distribution is much 
 like that of L. dmnoxii. 
 
 48. Lafrea ihtmosa (Fleming). 49. Laftea graciUima (Alder). 
 
 HALECID^E. 
 
 Trophosome. Hydrothecae alternate, reduced to the form of saucer-shaped hydrophores, usually 
 Itorne on tubular pedicels; margins even, often reduplicated several times, and surrounded by a circlet 
 of bright, bead-like dote. Hydranths large, with conical proboscis, not capable of retracting within 
 the hydrophores. 
 
 Gonosome. Gonangia producing planulse, and usually different in the two sexes, that of the 
 female often being surmounted by a pair of hydranths. 
 
 HALECIUM. 
 The single genus can be identified by the characters given above. 
 
 A'/-// to species of Halccium found in the Woods Hole rrrjinn. 
 
 A. Hydrophores borne on distinct pedicels. 
 . Stein fascicled. 
 
 b. Colony flubellate in form; aperture of female gonangium terminal, but not ^central. Pedicels 
 
 short H. hatecinum. 
 
 b'. Colony dendritic in form. Female gonangia with round lateral apertures. Pedicels short H. beani. 
 
 b". Colony with slender branches. Female gonangia as in H. Italccinum, but with the end emargi- 
 
 nate ff. gractte. 
 
 a'. Stem not fascicled, irregularly branched, annulated II. tenellum, 
 
 A'. Hydrophores sessile, borne directly on broadened shoulder of internodes of stem H. artifulosum. 
 
HYDKOIDS (>F THE V>"OODS HOLY. REGION. 
 
 357 
 
 Halecium halecinum (Linn.). Fig. 50. 
 (Sfftulai'ia hull-etna Linn., Syst. Nat., p. l:i08. ) 
 
 e. Colony attaining a height of 6 to 10 inches, erect, rigid; stein fascicled, pinnately 
 branched, internodes short. Hydrophores on lung trumpet-shaped pedicels, margins frequently 
 reduplicated. 
 
 (I'liiiiixniiii: Female gonangiu in rows on upper side of branches, obconic in outline, with the 
 aperture on one side of the truncated top, surrounded by a collar-like rim surmounted by a pair of 
 hydrauths. Male gouophores slender, oblong-ovate. 
 
 DixtriliiitSoii. Abundant throughout the Woods Hole region, growing on shells, stones, etc., in 
 shallow water. 
 
 Halecium articulosum Clark. Fig. 51. 
 (Tr;m>. Conn. Aeml. <>!' Sri. , vol. in, |>. (;:>.) 
 
 e. Colony sometimes attaining a height of almost 2 feet; stem fascicled, branches very 
 long and slender, the ultimate branchlets being pinnately arranged like those of the family 1'lu /- 
 Im-iiln: Hydrophone sessile, alternate, borne on the broadened distal ends of the almost triangular 
 inteniodes. Ilydranths very large, with about 20 tentacles. 
 
 50. Ifali i-iii in liiilerinam (Linn.). 
 Gonangium bearing Hytlranths. 
 
 51. Halrr/ii/n <(i-ti/-iilnxn)n. ( 'lark. 
 A. Hydranth (enlarged). 
 
 inn Hineks. 
 
 <ln<jsom.e. Female gonangia obovate, with a latero-terminal aperture. Male gonangia long, 
 slender, subeylindrical. 
 
 Distribution. Long Island Sound (Ferrill). The gigantic specimens referred to were secured by 
 the Fi*li ll<i !<!;, station 7051, lat. N. 40 46'; long. W. 70 43'. Depth 31 fathoms. The largest specimen, 
 and it is probably the largest known specimen of the Hukmlsr, is now in the U. S. Fish Commission 
 collection at Woods Hole. 
 
 Halecium tenellum Hineks. Fig. 52. 
 (Ann. and Mug. of N'at. Hist., 3d. series, vol. vm, p. 252.) 
 
 Trnphomme. Colony very small, not over half an inch in height; stem not fascicled, delicate, 
 irregularly geniculate; branches straggling, irregular; internodes very long and irregularly annulated. 
 Hydrophores borne on very long, tubular pedicels, irregularly arranged. 
 
 Gonomme. Gonangia borne at origin of pedicels, very large, oblong-ovate in outline. 
 
 Diiti-!lnit!i)ii.\ find this species mentioned in my notes as occurring at Woods Hole, but the 
 specimen seems to have been lost. The figure is from an English specimen. 
 
358 
 
 BULLETIN OK THE UNITED STATES FISH COMMISSION. 
 
 Halecium beani (Johnston). Fig. 53. 
 I Tfniii htaui Johnston, British Zoophytes, p. rjo. ) 
 
 Colony 2 to 5 inches high, branching in a dendritic manner, more delicate than //. 
 ii; stem fascicled, branches slender,, the internodes divided by slightly oblique nodes. 
 Hydrophores much as; in If. hnlecixum. 
 
 Gonowme. Female gonaiigia mitten-shaped, with the aperture lateral, representing the cut-off 
 thumb of the mitten. Male gonangia oblong-ovate. 
 
 Dixti'iliiitiuii. Found growing mi bivalve shells at Woods IJule. 
 
 A. 
 
 r>3. Jfalrcium beani (Johnston). 
 
 54. Halecium gracUr Verrill. 
 A. Hydrophores (enlarged) . 
 
 Halecium gracile Verrill. Fig. 54. 
 ( Invertebrated Animals of Vineyard Sound, p. 729.) 
 
 . 
 
 
 Trophogome. Colony profusely branched; stem fascicled; branches ascending, slender, picnately 
 arranged, with slender internodes separated by oblique nodes. Hydrophores much as in II. hakdnum. 
 
 Oonosome. Female gonangia much as in II. linlcriiiiiin, but with the end emarginate. Male 
 gonangia oblong-ovate. 
 
 Dittribution. Buzzard's Bay; Vineyard Sound; near New Haven, on floating timber (Verrill). 
 
 Professor Verrill has kindly sent me a type specimen from which the. figures were drawn. 
 Although hard to differentiate succinctly from H. lialccinum, it has a very distinct faciea and mode o 
 growth. 
 
HYDROTIW OK TITE V, 
 
 "659 
 
 SERTULARID.^E. 
 
 T:-:i;i!i<:n>iii<'. Ily.lrotlu' "e sessile, more or less ad:u\tt' to t:i" stem, tip.'! :irr:mg."l on both sides of 
 tne - i-.uiHies. llvdranihs with conical pr.ibosei- anil a single whorl of lilimvni tentacles. 
 
 Gonoxome, Son '>': planuKe. Xo medus;e. 
 
 i-i< ';/' 
 
 , -ill:, found in tin 1 \ViKnlt /In!'' 
 
 .\. Hydrol'.i'.'c:]' in sirii'i!;. < : , ;i Kitr t<i c.u-h iiUrniin!' 1 m the - I'.MII or !>ran;-h. 
 
 11. Opcl'culmn. v ', ' ,i pieces ................................................................... '//</ /arm. 
 
 0,'. ' M'ei'cnlnm, when prc^'tit, in one piece imly ............................................................... Diiiln'tin. 
 
 A'. Hydrothec D, subopposlto, usually ih-rjily Immenied more iiiMi: two in c.ii'li jciint ufstcni en- hnmch .......... Timim-in. 
 
 A". Hyilrnt!K;i';v >' riri!>* ;iMrrn : 
 
 a. Hydrotheceffi placed on oppo tte sides of Htexn ^n 1 ' branches ............................................. .svr/^ ' 
 
 (f'. Hyilriitilrr:i; |il:'.l-r ! oil lilc UMIlt ill' hrilllclK-^ lillil rlir\-|Ml ^llrniMU'l;' iii ;hr ri\:!l! mill icfi ............ ii't'ilnt'tiu'ii, '<'. 
 
 8EETULARIA. 
 
 Ti-i>i>inKiinii: ( 'olony usually lininchcd; stfinsand lirandus iliviilcd into reiriilar intennxles, each 
 of \vliich bears a pair of -triclly o|i|Hisite liyilrothce.-i-. Hydrothecffl either witliout an operculnni or 
 with a very dclie-.it.- one eniniiosi'ii of two pieces. 
 
 <iiin(jxn,ii<'. ' ionaniria without an internal marsupium. 
 
 Key in tpeciet of Serttda/ria found in ///<' \\'n<ni.-< lll< ni/ii/u. 
 
 A. The two hydrothecffi comporing a pair ^I'iircrly ti niching each other in front .................................. N. p u mil" 
 
 \'. The two hydrotheeii' in contact inrat leust llalf their lenj;l!i. 
 
 a. The width of a pair of liy.Iroiliccic at ;hcir IKI.M/S considerably less than di.-tancc from iKittoin of 
 
 liydrot'ieca- !o ill" iiMil,> ^clow ................................................................ S. cni'iiiclnn , 
 
 a'. The widtli ol" a pair of iiy-lrot!ici-:i' a! their bases not in ltd] less than distance from bolt out of hydro- 
 
 ther;c to the node below ...................................................................... >'. COmpiatt, 
 
 Sertxilaria pumila Linn. Fi,u'. ">"i. 
 (Syst. Nat., p. l::oii. ) 
 
 Trophosome. C'olony final 1, branehed 
 or unbraneht'd; stem divided into regu- 
 lar internoiles, each bearing a pair of 
 hydrotheca?. Hydrotheeie slotil, rc<ru- 
 larly curved, the approximated sides of a 
 pair not in contact; aperture bilabiate, 
 often showing a very delicate Operculnm 
 composed of two valves. 
 
 < niiiiiKoiiii'. ( Jonangia ovate, witli a 
 short pedicel and a terminal collar con- 
 taining the aperture. 
 
 Dixtrilititioii. Rather common in the 
 Woods Hole region in shallow water. 
 Often found growing over seaweed. 
 
 i i/utuilu Linn. 
 A. side view oi branch bearinggenangimn. 
 
 Sertularia cornicina (McCr. ). Fig. 5fi. 
 
 (It: inn, a mi diriiii-iiin Mct'r., (iyuinophthalinata of Charleston Hurlxir, p. 20-1.) 
 
 ii'. Colony usually of a single upright stem not over half an inch high. Hydrothecse 
 more slender than in ,s'. piniiilii and the pairs are in contact for a considerable part of their contiguous 
 sides. Colony almost invariably overgrown by a campanularian (HebcUn rrtlearattt) which the original 
 describer took to be a part of the sertularian, the campanularian disposing its curved tubular hydro- 
 thecse symmetrically in pairs above the pairs of hydrothecfe of the sertularian. 
 Gonosomc. Unknown. 
 
 l)i*li-iltiith>i.Vmcy&n\ Round, 8 fathoms on Halecium gracile, and on Xontern (Verrill). My 
 specimens were sent by Mr. \Vahnsley to Professor Osborn, of Hamline University, lalieled "S. pumila." 
 
 gene 
 
 i A satisfactory classification of this ijrmvp is still to be devised. The one adopted here will do fairly well for the 
 ra and species in the territory under consideration, but would be unsatisfactory it applied to the Sertularidsc in general. 
 
360 
 
 BULLETIN <1V THV. UNITED STATIN KfSII 
 
 Ssrtularia complex.a Clarke. Fig. 57. 
 (Bull. Mil". Comp. Zool., vol. V. X.>. in. p. lil'i. i 
 
 Ti-iiiihiixnnii'. Colony an unhranclu'd erect stern uHaijiin^ a height uf about three-fourth. 1 -' inch' 
 - tubular, abruptly curved outward dist:dly, aperture bilabiate; the luo hydrothecse of a 
 pair ailnate for more tluin tlieir proximal half. Stem hiternodes below Iiyilrci1hei-;e slender, showing 
 immediately below the h\ dml'ieca- short internal, cliitindiis |inu-esses pointing [downward from the 
 hydrothi'cal Hooiv. llvdran'.lis with conical |ir..li.wis and ab<n;i -0 tentacles. 
 
 Qonotome. < ;onani;ia [irodiiei'd iHiially in pairs at font of stem, ovoid in form, beautifully and reg- 
 ularly annulaU'd, ivsemblinj; Chinese lanterns, collar terminal, \vith circular aperture and o]iercnlum. 
 
 Dixli-iliiiliiin. Found by Mr. Walmsley near Woods Hole, and afterwards by myself, jfrowinj; in 
 ;/rei'.t quantities over seaweed dredged from the bottom near Nobska 1'oint. 
 
 .")li. *i ,'l/iliiriit rwith'hif >r<-Cr.. upon which ll<l>:lln fi>fi'<i,-<itii lA.^.j 
 
 is Lrrmvint: n-^ n |>arusitf. 
 A. Lateral view. H. Front vi<'\\. 
 
 ."7. >v rlt/l'ti-lii cii)iii>lt'.,-(i Clarke. 
 
 This interesting sjiecies was originally found by the li/nke off the coast of Yucatan, then reported 
 from Australia by Professor Bale, and finally proves to lie common near Woods Hole, where it has 
 doubtless often been mistaken for >'. /iinui/n, 
 
 DIPHASIA. 
 
 Trcphosome. Colony regularly branching; stems and branches regularly divided into internodes, 
 facli of which bears a pair of opposite hydrothefje. Ilydrothecal margins even or sinuous, with an 
 internal operculum consisting: of a single piece. 
 
 < iiiimaiiini'. Cionangia cleft above into leaf-like segments, and containing a spherical, internal 
 marsupial chamber. 
 
 Ki a In .<tii'i-i?s uf Di]>lnixiii jniiiitl in Ilif Wiintlx Hull' ivi/inii. 
 
 Width of a pair of hydrothecse at base nearly equal to their length D. fallax, 
 
 Width of a pair of hydrotheca" at haso not much more thnn half their height D. rosaccn. 
 
HYDKolUS OF THK WOODS HO I/I-. Kl.OIO'N. 
 
 Diphasia fallax (Johnston). Fig. ">S. 
 (SertulaHa/allaxlolspaton, British Zoophytes, 8th edition, p. 127.) 
 
 Ti-oiiliiimiiiit'. CuKiiiy branched, the terminal brandies often abruptly curved so as to form a hoo k 
 or short coil. Hydrothec;e stout, with a wide, sinuous margin dosed liy an operculum hinged to it 8 
 inner .side. 
 
 Uimoxinnf. Female gonangia with four leaf-like cxi)ansions above; male gonangia with four 
 terminal spines. 
 
 h'lxlriliution. Shallow water, often grow- 
 ing on other hydroids. A specimen found in 
 the U. S. Fish Commission collection at Woods 
 Hole is labeled "K. by S., Sankety, Nantucket, 
 23 fathoms, V. N. E." Off Watch Hill, 17 to 
 21 fathoms. (Verrill. ) 
 
 Diphasia rosacea (Linn.). Fig. 59. 
 (Kertuluria rusncin Linn., Syst. Nut., 130U. ) 
 
 Tfojiliiixamt'. Colony branched; branches 
 more slender than in D. ful/a.r, and more widely 
 separated. Hydrothecu 1 delicate, transparent, 
 slender, tubular, abruptly bent outward near 
 the middle; aperture facing nearly upward, 
 sinuous, dosed with an internal operculum con- 
 sisting of a single piece. 
 
 ti'iiiiiiisome. Female gonangium pyriform, 
 longitudinally ridged, with two prominent 
 pointed processes on top, and a round internal 
 marsnpium; male gonangium "pyriform, curved 
 toward the base, traversed* by longitudinal 
 lamellated ridges, which rise above into spi- 
 nous processes around a slender tubular orifice." 
 (Hincks.) 
 
 Distribution. Fisher Island Sound, 9 to 11 
 fathoms. ( Verrill. ) 
 
 SERTULAEELLA. 
 
 Ti-iijthoxouif. Colony usually branching; stem and branches divided into regular internodes, 
 each bearing one or two hydrothecsc. Hydrothecie strictly alternate, borne on opposite sides of th e 
 branch, usually with toothed margins provided with an operculum consisting of more than one piece. 
 
 diniomme. (ionangia as in Sertularia, but usually more or less annulated. 
 
 Kdj to ipeciesofSertufaretta found in Hie Woods Hole region. 
 
 A. Hydrothecal margin without teeth or operculum 
 A'. Hyrtrothecal margin with three teeth 
 A 1 . Hydrothceal margin with 4 teeth. 
 
 a. Teeth obscure. Hydrothcea fusiform, deeply annulated orwrinkled tnmsversply S. rugosa. 
 
 a'. Hydrotheese very large, sometimes corrugated above. Branches approximate S.gayi. 
 
 a". Hydrothoccc medium-sized, smooth. Branches irregular and distent , S. trirurpidata. 
 
 Sertularella abietina (Linn.). Fig. 60. 
 
 Trophonome. Colony pinnately branched; branches thick and coarse, approximate, divided into 
 internodes, each of which bears one or two hydrothecso; nodes oblique. Hydrothecse large, alternate, 
 bulging below and narrowing above to a tubular neck with a round, even aperture without an 
 operculum. 
 
 59. Dipliatia rosacea 
 (Linn.). 
 
 ' *.v i 'lnl<ir in nliirfiiia Linn., Syst. Nat., p. 1307. 
 
3(>0 HTLLKTLN ill'- 'I'll : I'NITKU -T.VTICS K1SH COMMISSION. 
 
 fiiiiiiixniin'.- -i ionangia "suhscssile, ovate, smooth, with an even, shortly tubnlous mouth." 
 (Hineks. ) 
 
 I>ist,-il,nt'ii>it.\ specinu-n in the 1 . S. Fish Commission collection at Woods Hole bears the label: 
 "E. by S., Siinkeiy light. 20 lath." 
 
 This species has always hitherto been placed in the genus ,V^/./,-M. Its strictly alternate 
 . Kydrothecic, however, make it necessary to consider it. a s,-i-lnl<ii-<'lln in accordance with the definition 
 given above. 
 
 M. x,;-inl,u-tn<i niiiitinn (Linn.). cl - KcrtulnreUn Iricuxijiilata (Alder). 
 
 Sertularella tricuspidata (Alder). Fig. 61. 
 i Sertutarla trirusiiidata Alder, Cat. Zooph. North and Durli., i>. 21.) 
 
 niie. Colony slender, branches alternate, divided into regular internodes, each of which 
 bears a hydrotheca. Hydrothewe cylindrical, slightly curved, distant, with a 3-toothed margin and 
 3-parted operculum. 
 
 <iiinuiimi: Gonangia deeply ringed, ovate, with a constricted tubular neck and circular orifice. 
 Di*ti-ili>rt!on.\ specimen in the Fish Commission collection at Woods Hole bears the label "E. 
 by S., Sankety light, 25 fath." 
 
 Sertularella rugosa (Linn.). Fig. <>'2. 
 
 (fit'iii'lui'i'i rni/dfn Linn.. Sy<(. Nut.. )i. 1308.) 
 
 Ti-iiiiliiiKonie. Colony minute, vjnbranched, or sparingly branched; intemodes short, each bearing 
 a' hydrotheca. Hydrothecic fusiforiii, very deeply and conspicuously marked with annular corruga- 
 tions; aperture quadrangular, rather obscurely toothed; teeth, 4: operculum composed of 4 pieces. 
 
 Gonosome. Gonangia like the hydrothecse, but much larger. 
 
 Distribution. Noank, on piles of wharf. Off Watch Hill, 17 to 21 fathoms. (Verrill.) 
 
 Sertularella pclyzonias (Linn.). Fig. 63. 
 
 (Sertularia polysonias Linn., Sj-st. Nat., p. 813.) ' 
 
 Tropliosome. Colony branched in an irregular manner, the branches alternate, but not equally 
 distant, divided into regular Intel-nodes, each of which bears a hydrotheca; nodes oblique. Hydro- 
 theca! swollen below, narrowing above to a margin, with 4 shallow teeth and an operculum of 4 pieces. 
 floiiomiiie. Gonangia ovate, corrugated, with a short pedicel and quadrate aperture. 
 I >;.-,! rilmtirm. "Off New London, 6 fath.; Gardener Bay, 6 to 8 fathoms; Block Island Sound, 17 
 to 24 fathoms." (Verrill.) 
 
HYDROIDS OF THE WOODS HOLE REGION. 
 
 368 
 
 Sertularella gayi (Lanix.)- Fig. 64. 
 i Xri-tiilnriu i/iii/i Lamx., Kxpositicjn Methodique, p. 12.) 
 
 Ti-n/iliiixoiiie. Like the last, lint much more robust. Branches regularly pinnate and approximate. 
 Hydrothecse much larger, often corrugated on the upper side. 
 
 tliiiKHSiiiitr. Gonangia with a 2-toothed aperture. 
 
 Digtrihittlon.A. specimen in the 1 T . S. Fish Commission collection at Woods Hole bears the label 
 "E. by S., Sankety Light, Nantiicket, i"> fath." This specimen has much larger and coarser hydro- 
 thecw than specimens from Kngland, and may represent a distinct species. 
 
 62. Sfrtularella rugosn (Linn.). 63. tyrtnltirclla jioli/:onias (Linn.). 
 THUIAEIA. 
 
 64. Sertularrtkt <jni/i (Linn.). 
 
 Trophwonif. Colony branched; stem and branches divided into 
 internodes each of which bears more than two opposite or subopposite 
 hydrotheae which are usually deeply immersed in the stem. Hydro- 
 thecse tubular, or flask-shaped, with bilabiate apertures. 
 
 Gonosome. Gonangia much like those of Sertularia. 
 
 Key to species of Thuiaria found in the Woods Hole region. 
 
 A. Stem long and slender, bearing slender branches which subdivide dicholomously. 
 Gonangia bimucronate. 
 
 a. Hydrothecse free for about their distal one-third T.argentea. 
 
 a'. Hydrothecse immersed almost to the orifice T. cupressina, 
 
 A". Stem a'nd branches rigid, the latter stiff and subverticillately arranged. Gonangia 
 without mucronate processes on end T. thuja. 
 
 Thuiaria argentea (Ellis & Solander). Fig. 65. 
 i&'ilularia argentm Zooph., p. 38.) 
 
 Trophoeome, Colony breaking up basally into long, slender main 
 branches which give off spirally set, closely approximated secondary 
 branches which branch dichotomously, each forming a graceful flabellate 
 structure; internodes rather slender, each bearing a group of several 
 hydrothecse. Hydrotherae subalternate, tubular, their distal ends curv- 
 ing gently outward, so that about the terminal one-third is free; aperture 
 armed with two opposite teeth, one much longer than the other. 
 
 Gonosome. Gonangia with two lateral projections and a central 
 terminal orifice. 
 
 Distribution. Vineyard Sound, Long Island Sound, and other parts 
 of the coast, Very common in depths from 1 to 20 fathoms. 
 
 65. Thuinria argentea (Ell. 
 A. Gonangium. 
 
3G4 
 
 Hl'LI.KTIN OF TI1K TXITKD STATES FISH COMMISSION. 
 
 Thuiaria cupressina (Linn.;. Kig. till. 
 
 (St : ftii/"<>" ''!;/<' *>///<( Linn., Syst. Nat., p. 130H.) 
 
 Trojilinxomi'. Colony consisting nsiuilly of a single very long and graceful central stem which 
 gives off alternate branches which again divide diehotomously into long alternate branchea; giving the 
 appearance of a verticil late arrangement. Inter-nodes much shorter than in the last species, each bear- 
 ing several pairs of suboppositc hydrotheca-. Hydrothec;e immersed nearly to their ends, tubular, 
 rather straight, with a not very pronounced bilabiate aperture. 
 
 tiiniiiMiuii: ( ionaiiiria borne ill rows on upper sides of pinnules, shaped like those of T. argi-iilen. 
 
 Dixti-ihiitinii. Vineyard Sound (Verrill). A specimen in the I'. S. Fish Commission cullection 
 at Woods Hole is labeled, "K. by S. Sankety Light, L'5 fath." 
 
 ThutarlaCHpre&tna(l,lim.). A. GonaiiKia. fi7. Thuiariu thuja (Linn.), 
 
 Thuiaria thuja (Linn.). Fig. 67. 
 
 (Xrrtnltiriu thuja I. inn., Syst. Nat., p. 1308.) 
 
 TrophoHonie. Stem rigid, sharply and finally geniculate, without branches on lower portion; 
 branches forming spirals, each diehotomously branched and forming a flabellate structure. All of the 
 branches and branchlets are stiff and harsh, very different from the graceful structures of the preceding 
 species; internodes very thick, each bearing several pairs of closely approximated subopposite 
 hydrotheca?, the top of one often reaching to bottom of one immediately above. Hydrothecse tubular 
 somewhat swollen below, apertures with two rather inconspicuous opposite teeth of about the same sine. 
 
 G/onOBome. Gonangia ovate, without lateral spines, and with a short collar and round aperture. 
 
 Distribution. Off Xantucket. (Vinal Edwards). 
 
 IIYDKALLMANIA. 
 
 imr. Stem branched, the branches plume-like. Hydro- 
 thecse in groups on one side of terminal branches, arranged in an alter- 
 nate manner, curving to right and le:t. 
 
 Gonosonie. Gonangia ovate, with a terminal aperture surrounded 
 by a slight collar. 
 
 Hydrallmania faleata (Linn.). Fig. 68. 
 
 (HiTtiiliii-iilJ'nlriilii Linn.. Syst. Nat., p. 1309.) 
 
 Tropliosomi'. Stem slender, without hydrothecse; branches plume- 
 like, the branchlets divided into internodes, each of which bears a group 
 of several hydrothecse on its front or upper side. Hydrothecfc fla.sk- 
 shaped, swollen below, narrow above, curved distally and ending in a 
 bidentate aperture with an operculum. 
 
 Gonosonte. (ionania as described above. 
 
 Disti-iliiitivii. C'omni'.in in rather deep water throughout the Woo<ls 
 Hole region. 
 
 
 68. ITu'lraltmninn falcata (Linn.). 
 
 A p lirt jon of brand), side view. 
 B. Gnnangium. 
 
- .1 i ii i (FOODS BOM REOIC 
 
 PLUMULARID/E. 
 
 ii UK'.- I lydrothi'Cif senile, usually admit'' by one side, arranged on the upper side- oi 
 the hydrocladia or hydrotheca-beftring brancblete. Nematophores 1 always present. 
 
 Gonogome.4 ionaiigia often inclosed in protective contrivances, sucli as modified branches or pod- 
 shaped receptacles called " corluil;c." No medu-;". 
 
 Ki'if In (ft'nri'ii nj f'/iiniiil'i i-iil;t' i'u/in'1 tu lln' }\'(niil>: //ii/-' region. 
 
 A. Kemftlophoreg tmmp!t-baped, nut immovably lixed to the liydrothccic. 
 
 u . Hntnchini: ilichoiomoiis, the hydmelatlia springing 1'rom tin.- ui-prr side of the branches M<>/ii>*li> : i'ti<t*. 
 
 a'. Braiirhinx strirllv iiiiimiir, the hyih'oeladi:i, or some of thorn, forked .Si'/<(':o?/-/i'/m. 
 
 n". Bniuchlnx verticil late or scattered. Ou-nosarc canalioulntC'd in muin stem .Intniaulnrin. 
 
 A'. Xeinatophores not tniinpct^luM^' 1 ! iiniiKn'i'liiv- iixo'1 to hydrothoi-Li' or oilier parts of polony. Gonangia 
 
 ]iroi'T!-''l I, -j.nvi;il n-ii;!lly forke-l hranc-hcs bearing neuiiitophoiv* \\'iiluiiu lu'ilrothofie (fadocaryxt, 
 
 MONOSTJSCHAS. 
 
 Tm//lniMiini: Colony dichotonionsly tii'anchcd. Ilydfoclailia liornc on npiu-r ^ides of liranch es. 
 G'onownu 1 . Gonangia ovoid, borne at bases of liydrol!icc,-i . 
 
 Moiiostsechas quadridens (ilcCr. ). I-'i;r. MI. 
 
 i il-tfin i/iiiiili-ifli'n* Mrl'rM'ly. I'rfir. Klliott Sor.. Vol. 1. N'o. 1. p. 1!W. I 
 
 Ti-i'iilinxnnii-. Coloii'V erect, composed of a main stem with branches which 
 themselves branch dichotoiiioi.vly, hi-ariiis; hydrocladia at their points of junction 
 and also on their upper sides; hydrocladia composed of internodes, every alternate 
 one of which bears an hydrotheca. 1 1 ydrotlieca' cup-shaped, witli even margins, 
 initiate lor about half their length. Xematophores trumpet -shaped, three asso- 
 ciated with eai-h I) vdrotlieca. and usually two on each iuternode of hydroeladium 
 that does not bear a hydrotheca; a row of ncmatophoivs is also found on the upper 
 side of each branch from which hydrodudia s[irin<r. 
 
 fioiioaiiiin'. (ionanji-ia ovoid or pyril'orin, borne on short pedicels Justin-low c.s. )i,,iu,ftu; -IMS, im ,i- 
 the hydrothec;e. '''''"'- <MrCr.). 
 
 l>i.-!rilniliiin. Dredged by the .\lluili-mtx near Marthas Vineyard. 1'epth, 22 fathoms. The 
 species is common southward to the West Indies in moderate depth. 
 
 8CHIZOTRICHA. 
 
 7Vn/i/i"w///'. Colony consistiiiir usually of a cluster of simple, upright stems, giving forth 
 hydrocladia in a pinnate manner. Hydrocladia in mature specimens forked. 
 
 iliiinixitiiii'. (ioiuingia ovoid, tubular or cornucopia-shaped, borne on the main stem, brahehes, 
 or hydrocladia. 
 
 A,'// In x/H-i'ii-x i,f Xrhi-.iilrii'litt jimml in Ilif }\'niiiln /full' re.yion. 
 
 An hyilrotln-i'ii in tlic axil of wicli liyilnicladiiiin S'. It'iiflln. 
 
 N'o hv.l i'. ,! i n'l'; i in tin 1 ;ixil> of tlu 1 hydrocijuliii N. iiritrilliinil 
 
 Schizotricha tenella ( Verrill ). .Fig. 70. 
 
 i Ilinuntiiriii liinllit Vvrrill. Irnvrlrliratnl Animals of Vini'Vanl Soniul. p. 731.) 
 
 'l'i-iiiiliiix/iiiii: Colony iri'the form of very I'.elicate white ])lumes, 1 to!! indies high, each plume 
 consisting of a central stem giving off alternate hydrocladia. with hydrotheca at l>ase of each; 
 hydrocladia often forked in mature specimens, with internodes and hydrothecie much as in the last 
 species, but with an additional short internode often intercalated. Xematophores as in the last species', 
 except that there is hut one to eadi intermediate internode. 
 
 1 The iH-niatophoK-y an- minute trumpet shaped or tubular organs composed of chitin and usually associateil \\ ith 
 the hydrothecffi, two. one on each side. iH'ini; fiaind near where the margin of tile hydrotheea joins the stem to which it 
 is adnate, and one jn:-t in front of the bottom of the hydrotln ca. dther.-i.aie found on tin- branched, stem, mid protective 
 c-ontrivanees which iii'-lose the ,i;oiiiin^ia. Tlie nemntophores contain liijflily remarkable strm'tnres known a-' lafcOBtyJea 
 that are e;io.-ili!,' of rnorinoiis eNinei, ,n. 'i'liey ar-- morphol.'tric:!!!-.' " pf ;^on<" of the colony. 
 
lU'LI.KTlX UK THK I'MTKU >T.\TK.S KISH COMMISSION. 
 
 diHiiixniiii'. (ronangia curved, cornucopia-shaped, borne on slender pedicels at the liases of the 
 hydrothecii' and having one or two nem.'itophores on the basal portion. 
 
 Itixti'iliiitinn. Found abundantly on the piles of the wharves at Woods Hole and Vineyard Haven. 
 Off <i;iy Head. S to 10 fathoms; Vineyard Sound, 8 fathoms. (Verrill.) 
 
 verrill). A. Partof hvrtrooladmni (enlarged). 
 
 71. Nr'/"'. l:'ii'fi:l in'">-ill:nt< iSfll'M. 
 
 A. 1'iirt of hyilriirhuM'mii M-nhir.i;c(l .. 
 
 7: 1 . AjUfnmtlaria fmtennfna iLinii.). 
 A. 1'jirl of hydrocliuliinu icnlargod). 
 
 Schizotricha gracillima (Sarsl. l''i^. 71. l'/niiiii/ni-i<i n-n-iUii Clark. 
 ( lluiniilumi iii-iii-ilUnui Sill's. Biilmg til Kiunlskuli om Dvivlivrt pnii vr</ HiivliiiiikiT.) 
 
 Trojilioxiiiiii'. Colony cdiisistinj; of a main stem, which j;ives off plumose branches near its base* 
 Branches consisting of a slender sliaft, giving off alternate rather distant hydrocladia, which are forked 
 and divided into rat her distinct interuodes which are Ions; and slender and separated by straight nodes. 
 Hydrotheni- small, cup-shaped, almost entirely adnate behind. A pair of trumpet-shaped netnatophores 
 are inserted just above the aperture of the hydrotheca, another single one below its base, and others 
 scattered rather irregularly along the hydrocladia and stem. 
 
HYDKOID3 OF THK WOODS HOLE KEOION. 
 
 367 
 
 i'. Gonangia subcylindrical, somewhat swollen below, not cun'ed, borne usually at the 
 origin and Workings of the hydrocladia. 
 
 fHntriliiitinn. Eastport, Me. (Verrill). It is altogether probable that it occurs in the deeper 
 water in the Woods Hole region. I have included it here to enable collectors to identify it if found. 
 
 ANTENNULARIA. 
 
 Tmjiltosome. Hyrocladia arranged in verticals or whorls around stem. Stem with canaliculated 
 ecenosare, the canals being just under peridenn and not well seen except with transmitted light. 
 
 (jiiiio&ime. Gonangia borne usually in the axils of the hydrodadia, not protected by gonangia or 
 other special contrivances. 
 
 73. AiiteiiniilnriaamcricunaHutting. 73 A. Part of hydrocladium (enlarged). 
 
 - 
 
 74 A. 
 
 73 A. 
 
 1 
 'rr j 
 
 74. Aiilrnnnlaria riiijnmi Xmtiiijf. 71 A. Part of hydroeladium (enlarged;. 
 
 Key to species of Anlenmtlaria fuuml in the Woods Hole region. 
 
 A. A node between the first hydrotheca on each hydrocladium and the stem from which it springs A. antennina. 
 
 A'. No node between the first hydrotheca and stem. 
 
 o. At least two nodes between adjacent hydrothecte A. americana. 
 
 a'. Hydrocladial nodes distant and usually absent , A.rugota. 
 
 ' 
 
 Antennularia antennina (Linn.) Fig. 72. 
 
 _ ___ (fierlularia antennina Linn., Syst. Nat., 1310.) 
 
 Troplwsome. Colony composed of a cluster of upright stems with whorls of hydrocladia at 
 regular intervals; hydrocladia borne on stout processes from the stem, the first internode being without 
 
Hri.LK'ilN 01' THK UNITED STATES USH COMMISSION. 
 
 hydrotheea, the next with one on its proximal half, and tho rest of the hydrocladium being made up 
 of alternating hydrotheeate and intermediate internodes. Hydrothecse cup-shaped, margin entire. 
 Nematophores trumpet-shaped, a pair near the top of each hydrotheca, one below its base in front, 
 two on eacli intermediate internode, and others on the stem. 
 
 ('.'niiiixiiiiH'. Gnnangia borne on bases of hydrocladia, ovoid, deep, with subterminal aperture. 
 Dixii-ilniiiiiH. Off Gay Head, 18J- fathoms. Newport Harbor; Woods Hole; off Block Island. 
 I, <M Mi-go Gray. ) 
 
 Antennularia americana Nutting. Fig. 73. 
 Monograph of Amerind! H\ ilroUl^, iart 1. The I'linmilarida-, p. ti9.) 
 
 Ti-ii/iliniaiiiii'. Colony composed of slender, erect stems bearing hydrocladia usually in whorls of 4. 
 Proximal hydrothoca on each hudrocladium borne on a long process from the stem, there being no node 
 between it and the stem. Otherwise the arrangement of the internodes, hydrothecte, and nemato- 
 phores are as in the preceding species. 
 
 (IIIIKIXOIIII: Gonangia oblong-ovate, with a subterminal lunate aperture. 
 
 l>ift,-il,i<t'uiii. Off .Marthas Vineyard, AHuilm**. Waters of Rhode Island (specimen from Dr. 
 H. ('. I'liimpus). 
 
 This species, although greatly resembling .1. nntfimiufi, differs constantly in the characters given. 
 In some cases, where a hydrooladium has been broken off and regenerated, there will lie a node below 
 the proximal hvdrothera. Otherwise the character is constant. 
 
 Antennularia rugosa Xntting. Fig. 74. 
 
 Mnnnj,'ni|.ii of AmiM-ii-nn Ilydroids. purl 1. Tho I'lunuilan.U-. p. 70.) 
 
 Ti-n/iliii.111,111'. The colony, consisting of upright stems which give off hydrocladia in whorls of 6 
 or 8, tin node lietween the proximal hydrotheca on each hydrocladimn and the stem. Hydrocladia 
 supported by a remarkable thickening of the perisarc on the lower side of the proximal portion of 
 each. Nodes very distant and irregular, but the interiors of the hydrocladia have numerous annular 
 thickenings of the periderm that somewhat resemble nodes. Hydrotheoio deeper than in the other 
 species. A pair of nematophores inserted on a level with top of the hydrotheca, and others scattered 
 along the fronts of the internodes and around the stem. 
 
 liiiiiiixiiiiii-. Not known. 
 
 l>ixti-iliiil!n)i. Off Marthas Vineyard, 46 fathoms. (AII/ati-Hsx.) 
 
 CLADOCARPUS. 
 
 nf. Colony branched. Hydrocladia not forked. 
 Nematophores neither movable nor trumpet-shaped. 
 
 friiinmonii'. Gonangia borne on the stem and protected by 
 special branchlets which spring from near the bases of the hydro- 
 cladia, and bear nematophores but no hydrothecne. 
 
 Cladocarpus flexilis Verrill. Fig. 75. 
 (Report Com. Fish and Fisheries, 1883, p. 617.) 
 
 Trophosome. Stem not fascicled, long and slender; hydro- 
 cladia pinnately arranged, alternate, not forked, divided into 
 internodes, each of which bears a hydrotheca, and has its cavity 
 divided by internal ridges. Hydrothecse deep, subcylindrical, 
 aperture horizontal, with a single strong anterior tooth and a 
 number of shallow lateral teeth or sinuations. Nematophorea 
 tubular, a pair slightly overtopping the hydrothecal margin, and 
 a single one below each hydrotheca, its end not rising much 
 above the level of the bottom of the latter. 
 Gotiosome. Gonangia growing on front of stem, protected by special branches borne on the bases 
 of hydrocladia and branched like deers' horns, each branch bearing a row of nematophores. 
 Dlxtrihution. Found in moderately deep water at various points along the Atlantic coast. 
 
 75. Clod0qarpu0jfcztfft Verrill. 
 
 A. Gonangia withjprutcctivc branchlets. 
 
HYHK01U- Of THh. WOODS HOLK REGION. 369 
 
 HYUROII) MEDUSA FOUND IN THE WOODS HOLE REGION. 
 
 A monographic account of the medusa? is in course of preparation by an eminent 
 authority, and the present writer therefore does not desire to discuss the medusae in 
 a systematic way, but hopes that the key herewith presented will be of service in 
 identifying the medusre known to occur in the region. No attempt has been made 
 to describe new species or to define families, genera, or other groups. The classifi- 
 cation conforms, so far as possible, to the plan of the preceding part of this work 
 when the hydroid form is known. Otherwise the names are the same as those found 
 in Alexander Agassiz's work, North American Acalepha?. Almost all of the illustra- 
 tions are from specimens taken at Woods Hole and Newport, and sketched by the 
 author. 
 
 Ki'ii far tin i'li'ntitirittion nf tin' Hi/ilfoiil meilnmr foil ml in tin' Woods Hole region. 
 
 A. Ovaries attached to the proboscis walls mid never fnmid along the radial canals. Otocysts never present. 
 a. Radial canals I', unbranchcd. 
 b. A single conspicuous marginal tentacle, others, if present, much smaller. * 
 
 r. Proboscis not more than one-half length of bell cavity Euphysa rirffulata, ^ 
 
 c'. Prol.M>seis more than one-half length of bell cavity. 
 
 (I. A single greatly enlarged tentacle from which secondary medusae arise Hybncodon pmlifer. 
 
 /I'. One large and 3 much smaller tentacles. Xo secondary mednsre Corymorpha pendtda. 
 
 b'. Two conspicuous marginal tentacles. Others, if present, much smaller. 
 c. Bell with a distinct .-ij'ie.-il projection. 
 
 tt. Apical projection a lengthened cone Stomatocha apicata. ^ 
 
 il'. Apical projection dome-shaped. Tentacles bearing stalked iienmtoeyst batteries.. Kenimaria cladnphora- V 
 c'. Bell evenly rounded, without apicul projection. 
 
 (I. Tentacles bearing stalked batteries of nematoeysts Corynitis Offassizii- 
 
 d'. Tentacles IK irmal Pcrigonimusjoneri. 
 
 b". Four tentacles of approximately equal length. 
 
 r'. l'rol>oscis and tentacles very long and slender. 
 
 il. Bell outline subspherical Conine m/rabiUs. 
 
 rl f . Bell outline subeonical , Dipurena arnica. V 
 
 r'. Proboscis short, not reaching bell opening. 
 
 (I. Tentacles tightly coiled. Bell with s meridional lines of liwso cells Ertnplcumochracea^ 
 
 d'. Tentacles rudimentary. Xo lines of lasso cells Peiniaria tiarctta. 
 
 il". Tentacles functional. Harlial canals very broad ITydricMhys mirui. 
 
 ft" w . Kight tentacles of approximately equal length. 
 
 r. Tentacles strong, functional. Proboscis bearing secondary medusre Di/smorplmm fitli/umns. ** 
 
 ' '. Tentacles rudimentary. Xo secondary. medusa 1 titylactis hoopcri. 
 
 b" ff '. TwUacles more than s. of approximately equal size when full grown, and disposed at regular intervals. 
 
 c. \ large globular or snbconical process on apex of bell Turns rrticarta. * 
 
 r'. Bell evenly rounded above Turriiopsis nutricnla. < 
 
 yrrtr 'i\.ntacles in groups or bunches. 
 <. Kour clusters of tentacles. 
 
 '/. Proboscis small and slender. 
 
 e. A pair of erect elavate tentacles in each group J Xnnoitritbacliel. Y 
 
 /'. Tentacles much alike Bougainrillia mrolinwtis, 
 
 rl'. I'roboscis large and broad BougainviUia superciliarte, 
 
 i". Kight clusters of marginal tentacles Liszia ip-ata, Y 
 
 a'. Radial canals I, branched at their distal ends Willia ornata. v 
 
 a". Radial canals many, bell cup-shaped Orchinioina tentaevlala. 
 
 A'. Ovaries attached to the radial canals, often also to the proboscis. Otocysts usually present, 
 o. Radial canals 4. 
 
 b. Marginal tentacles 4. sometimes with lateral cirri. 
 
 i . Proboscis KSts; long, reaching far beyond the velum. .. 
 
 'I A swelling af base of each tentacle Eutima mim,-!* 
 
 d'. No swelling at bases of tentacles Eutima limpiia. y 
 
 c'. Proboscis short. Bell deep. 
 <l. Tentacles with lateral cirri. 
 
 e. Club-shaped appendages U'tween bases of tentacles , Hebella rtilearata (juv.). 
 
 r'. Xo club-shaped appendages. * 
 
 /. Two ot< K-ysts bet ween bases of adjacent tentacles Euclictlota rCT(riCTi?ri < *- 1 -'* 
 
 /'. Three otocysts between bases ,f adjacent tentacles Eucheilota duodectmalit. "^ 
 
 it'. Tentacles without lateral cirri Clytia bicopkvra (juv,), 
 
 Clylia noliformii (juv.). 
 ' . B. 1899 24 
 
;; : 7li I;I:J.I,KTIN oi TUI: r.N'LTKi) STATES KI-II o>\l M I---K.N. 
 
 b f . Marginal tentacles. It; or more. 
 
 i: Proboscis very long, reaehinsjfar below velum ................................................ Tium ji;natam..V 
 
 c'. Proboscis short, 
 
 il. Tentacles with lateral cirri at bases .................................................... llebclla e 
 
 i.l'. Tentacles without lateral olrri. 
 
 c. Bell disk-shaped. Proboscis without limhnated tentacles. 
 /. Otolithxou buses of liMitacles. 
 
 0'. Tentacles 24 nt liberation of medusa ........................................ Ol,,li,i ri 
 
 (Ill' If,, lnil<li**nliil 
 
 Obclia fabcllntnl 
 i/. Tentacles K; at liberation oi medusa .................................... fAiflittnelalmiisn. 
 
 tlbttttt flirfititi,uni. 
 
 nli, I in rnmniixfitnllit. 
 
 i' 1 . Bell deeper, its surface evenly rounded. 
 /. (>t4>litbs between base's of tentacles. 
 
 tj. Otoliths 8 (or more?). Mouth tentacles not thnbriated ...................... Ctytia bictiptwra. , 
 
 if. Otoliths 8. Mouth tentacles limbriatefl ................................. 7YrjMM dindemata. ' 
 
 !l". Otoliths numerous, with sense-bnjbs at their bases ........................ Kftfntheies fulleala. * 
 
 (/".Otoliths numerous. Tentacles with sense-bulbs and thickened '-knee- 
 
 pads " ................................................................. (,'on uatemus rcrtenf.'r 
 
 c". "Bell with a distinct dome-like apical projection .......................................... Onuinn siniitilarit. ' 
 
 a'. Radial canals N. 
 
 b. Bell very deep, shaped like a bishop's miter ................................................ Ti-m-lniiii'inn rfiyihtli*. ^ 
 
 b f . Bell subspherical. somewhat narrowed above. Mouth with fringed tentacles ........... Mfllct i-tuni niiiijHinttla. f^ 
 
 a". Radial canals more than s. 
 
 b. Mannbrium very short, hardly^distinfjuishable .............................................. ]tli<;jmi<l<,(l, * I, 
 
 b'. Mnnubrlnm well develoj>e<l. 
 
 c. Mouth without fimbriiited tentarles. Bell shallow ............................................. Kjnorr albitla. * 
 
 <'. >[outh \vith timbriated tentacles ......................... . ......................... /i/i/<,</m7</Ai ,/i;,, nfnu,l>,;t. 
 
 Ejiphysa virgulata A. Ag. 
 
 1 North American Acalepli^. |i. Is'.i. i 
 
 Bell quadrangular, thick, longer than broad. 1'roboscis short, tubular, without mouth tentacles. 
 Tentacles 4, of which one is much longer than the others, with a triangular base. Radial canals 4. 
 Velum with a sinuous inner edge. 
 
 f'vlrirotion. Tentacles with white liases and a pink stripe or band. Proboscis light yellow. 
 
 I have not seen this species, and the above description is condensed from that of Dr. Agassi*. 
 
 Hybocodon prolifer L. Ag. Fig. 7l>. 
 (Tout. Nat. Hist. T.S.. vol. IV. p.lil:'.. i 
 
 Hell ovate, evenly rounded, nnsyiitmetrical owing to great development of the single tentacle, 
 its surface marked with 5 meridional orange-colored bands, 2 of which start from the sides of the 
 base of the tentacle. Proboscis long, contractile, sometimes reaching nearly to the velum; no mouth 
 tentacles. A single very large marginal tentacle armed with conspicuous nematocyst batteries and' 
 bearing medusa 1 of a second generation at its base. 
 
 t'uliir. Superficial bands and base of tentacle orange red. 
 
 Dtsti-Hintiiiii. Taken in the tow at Woods Hole (Vinal Kdwards. ) The colored bands are not 
 easily seen in these specimens, which were collected in April. 
 
 This species can at once be recognized by its single greatly developed tentacle with secondary 
 medusse at its base. 
 
 Oc?Kyinorplia pendula L. Ag. 
 
 (Cont. Nat. Hist. I". S.. p. '.'TC.. The medusa is dcsrrilicil by A. Agnssiz in North American Acalcphie, p. 192.) 
 
 Bell deep, with the :tpex somewhat pointed, slightly nnsymmetrical owing to the excessive 
 development of one tentacle. Prolxiscis long, often reaching l>elow the velum. Tentacles 4, one being 
 much tM largest, but not bearing secondary medusa> at its base. 
 
 I'vloi: Proboscis light yellow; bases of tentacles light pink. (A. Agassiz.) >.)'.,. 
 
 Dlxti-iliiiHini. I find no record of this medusa having been found in the Woods link .region. 
 although the hydroid form from which il grows has been found 'here. Alexander Agassi/ rcpovtijit 
 from off Cape Cod. 
 
1IYDKUIUS OF THK Wool** Hnl.K KKUION. 
 
 371 
 
 Stomatocha apicata (McCrady). Fig. 77. 
 (Xnplicnia apicatn McCr. Proc. Elliott Soc., vol. 1, No. 1, p. 130.) 
 
 j/a/<>. Bell broad and shallow, with a long conical projection at its summit. Marginal tentacles 2, 
 very long, but capable of retracting into short, finger-like bodies as in the figure; rudiments of other 
 tentacles around the margin. Proboscis very large and bulky, composed of lobes that extend to the 4 
 mouth tentacles, which are pointed and reach below the velum. Radial canals 4. 
 
 Colors. Tentacles rich purple, tipped with olive green. Spermaries and basal part of proboscis 
 clear light emerald green. These colors differ greatly from those given by McCrady. They are taken 
 by myself from a living specimen. 
 
 Dinamatella cavosa Fewkes. 
 
 Female. Bell subglobular with a cone-shaped apical projection, the cone being shorter than in 
 'the male, and divided into two portions, a basal dome-shaped portion being surmounted by the 
 short subconical apical part. Tentacles 2, hollow, very long ; besides these 
 there are 6 rudimentary tentacles on the bell margin which bear pigment 
 spots at their bases. Proboscis very broad and heavy, reaching about to the 
 velum, and bearing four heavy lips which are not fimbriated. Ovaries form- 
 ing masses around the proximal part of the proboscis. Radial canals 4, band- 
 like, with irregular jagged edges. 
 
 Colors. General color light green. Ovaries yellowish white. Tentacles 
 greenish. Pigment spots orange, with a bright red dot in the center. 
 . Newport Harbor, August, 1890. 
 
 Gemmaria cladopliora A. Ag. Fig. 
 
 (North AiiK-rii-iin .U'iilr|>!i:r. |>. 1*1. 1 
 : ; 
 
 ik'll rather deep, the apical portion being elevated into a shallow rounded dome not sharply, but 
 still evidently differentiated from the re;=t of the bell. Tentacles 4, two of which are much the longest 
 and Vehr ruriou:- clusters' of nen'iatocysts borne mi i-liort stalks or pedicels. Proboscis scarcely reach- 
 
;.i LLK11N 
 
 THK UNl'TKJJ STATES KISH OOKMI88IOK. 
 
 ing the bell opening, constricted just above the 4 small lips or mouth-amis, and bearing the ovaries ou 
 the proximal portion. Radial canals broad. 
 
 Colors. The large tentacles light brown with a slight orange tinge at bases. There are bright 
 yellow pigment spots at the bases of the two rudimentary tentacles. 
 
 liiatrlftiillon. Collected at Woods Hole, August, 1899. 
 
 i'fnifi'jtli'n-1/ A. \K- 
 
 SO. Oiri/iiitif iigatfizii (McCr.). (After Miirbauh.) 
 
 Corynitis agassizii (McCrady). Fig. 80. 
 (Proe. Elliott Soc.. vol. i, No. 1, p. 132.) 
 
 Bell deep, orbicular, without apical prominence. Tentacles 2, very long, bearing stalked bat- 
 teries of nematocysts. There are also two rudimentary tentacles. Proboscis short and simple, with- 
 out expanded lips. Radial canals 4, not broad and bandlike, and with curious bulging groups of 
 nematocysts on the outside of the bell over the distal portions of the canals. 
 
 Color*. Not given either in the original description or that of Dr. L. Murbach, who first estab- 
 lished the connection between Coi-jiiiitlx ni/iiialii! and (leuniuiria i/einniiixn of MeCrady, the latter being 
 the medusa of the former. His figures are here copied by permission. 
 
 fHxti'iliiiti/in. Woods Hole. (I,. Murbach.) 
 
 Perigonimus jonesii Osborn & Ilargitt. Fig. SI. 
 (American Naturalist, IN'li. p. '27.) 
 
 Bell orbicular, marginal tentacles 2, long and hollow, alternately 
 with two eye-spots, which may indicate two rudimentary tentacles. 
 Proboscis short, not reaching much more than halfway to the broad and 
 strong velum. Radial canals 4, those leading to the large tentacles 
 broader than the others. 
 
 Cvlnrx. Xot given by the describers. The medusa buds, while still 
 attached, are a light salmon color in specimens kindly furnished me by 
 Dr. Hargitt. 
 
 hixtrilmtidii. Cold Spring Uarl>or, Long Island. 
 
 Coryne mirabilis Ag. Fig. 82. 
 
 (Cont. Nat. Hist. T. S., vol. IV. j>. 185.) 
 
 liell orbicular. Marginal tentacles 4, very long, each with a swollen 
 pigmented body at its base. Prolmscis very long, reaching far below the 
 l>ell opening when fully extended, but capable of Ix'ing retracted well 
 within the bell, suspended from the bell by a narrow, contracted por- 
 tion. Mouth a simple opening without mouth tentacles. The attached 
 medusa is longer, the tentacles closely coiled, and the proboscis retracted 
 within the bell and often having its walls distended with sexual products. 
 
 Colors. Specimens in formalin have the proboscis and tentacle bulbs light yellowish, 
 black. 
 
 Diitribulion. Collected at Woods Hole by Mr. George Gray . 
 
 81. Pvrigonimiu jonetli Osb. 
 & Harg. (After Osborn 
 & Hargitt.) 
 
 Eye-spots 
 
 

HYDROIDS OF THK WOODS IIOLK REGION. 
 
 373 
 
 Dipurena coiiica A. Ag. 
 
 (North American Aralepha?, p. 181.) 
 
 Bell a rounded cone. Marginal tentacles 4, rather short, each with a rounded knob on the diatal 
 end and a pigmented spot and eye-speck at the base. Proboscis long, when fully extended reaching 
 far below the rather broad velum, but capable of great retraction; attenuated proximally and swollen 
 dietally; mouth plain, without mouth tentacles. Radial canals 4, slender. Young specimens are 
 almost globular in form. 
 
 Colors. Distal and proximal ends of tentacles reddish. Eye-specks black. 
 
 Distribution. Naushon (A. Agassiz). 
 
 I have not seen this species; the above description is condensed from that of Dr. A. 
 
 A. 
 
 s:l. Krlnfilfiirn iicltramt A. Agr. 
 A. [.literal view. B. Aljornl view. 
 
 82. Cbrync mfmbills (Ag.) 
 
 B. 
 
 81. Pri!ai-iirtfaMcCr. 
 
 A. Mt'ilum from which the ova has been expelled. 
 
 B. Medusa expelling an ovum. 
 
 Ectopleura ochracea A. Ag. Fig. 83. 
 (In L. Agassiz Cont. Nat. Hist. U. S., vol. IV, p. 343.) 
 
 i Bell longer than broad, subpyriform in shape, the upper end being the smaller; surface orna- 
 mented by eight meridional bands of nematocyste, a band originating on each side of each tentacle 
 base and passing directly over the surface of the bell to its apex. Tentacles 4, short, usually carried 
 so closely coiled as to appear like mere knobs. Proboscis terete, not reaching to the bell opening, and 
 ending in a simple mouth. Radial canals 4. 
 
 Colors. Manubrium bright yellow proximally aWd'distally, the middle part being rose pink. 
 Tentacular bulbs ochraceous, with a red eye-spot on each. 
 
 Distribution. Abundant at Newport in August. Woods Hole. Probably common throughoat 
 the region discussed in this work. 
 
374 
 
 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 Pennaria tiarella McCr. Fig. 84. 
 (Proc. Elliott So., vol. I, No. 1, p. 153.) 
 
 Bell very deep, regularly elliptical in outline. Marginal tentacles 4, rudimentary. Proboscis 
 oblong ovoid, with both ends constricted, not reaching velum; mouth opening not apparent. Radial 
 .canals 4, accompanied with lines of dark pigment. 
 
 Colors. Manubrium and lines over radial canals deep pink, the latter being darker and more 
 brilliant. 
 
 D'utrilmtion. Common in shallow water throughout the Woods Hole region, especially in the 
 flatter part of the summer. Growing profusely on the piles of the wharf at Woods Hole and on the 
 
 eelgrass nearby. 
 
 Hydrichthys mirus Fewkes. 
 (Bull. Mus. Comp. Zool., vol. xin, No. 7, p. 22-1.) 
 
 Bell oval, nearly spherical, its surface dotted with nematocysts. Marginal tentacles 2, when first 
 liberated, afterwards 4. Radial canals 4, very broad, bandlike. Proboscis cylindrical, not reaching 
 the broad velum. The tentacular bulbs are without eye-spots. 
 
 Colors. Proboscis orange and yellow. Tentacular bulbs reddish. 
 
 Distribution. The type specimens were liberated from a colony growing on a fish, Sertola zonata, 
 which was brought into Dr. Alexander Agassiz's laboratory at Newport. 
 
 I have not seen this species, and the above description is condensed from that of the original 
 describe!-. 
 
 N.Y Dytmorphosa/ulffHratlt A. Ag. \. Lateral view. H. Ventral view. 
 
 Dysmorphosa fulgurans A. Ag. Fig. 85. 
 
 / l North American Aealepha-, p. 163.) 
 
 ;. Stylaftls kooperiUgetiooe 
 
 (after siyvrt'uos ). 
 
 Bell ovoid, its surface having a granulated appearance. Marginal tentacle* 8, rather stout, and 
 held somewhat stiffly, each with a bulbous expansion with a distinct eye-spot at its base. Proboscis 
 short, not reaching much more than halfway to the bell opening, and ending with four mouth 
 tentacles furnished with terminal rounded batteries of nematocysts. Specimens secured in August 
 had young medusa? growing on the upper part of the proboscis, and these themselves often show 
 budding medusa; of still another generation. Radial canals 4. 
 
 Colors. The pigment spots at the bases of the tentacles are bright orange red. 
 
 Distribution. During the summer, throughout the Woods Hole region. Agassiz says in reference 
 to this species that it is "sometimes so abundant that the whole sea, when disturbed, is brilliantly 
 lighted by the peculiar bluish phosphorescent color which they give out." 
 
 Stylactis hooperii Sigerfoos. Fig. 86. 
 (American Naturalist, vol. xxxm, No. 3&4, p. 801.) 
 
 Bell ovoid. Marginal tentacles 8, rudimentary. Proboscis very large and broad, not reaching 
 beyond the bell opening, greatly distended with sexual products at time ,of liberation, without mouth 
 tentacles or mouth. Eye-spots absent, Radial canals 4. 
 
HYBROIDS OF THE WOODS HOLE REGION. 
 
 375 
 
 Colors. Not given by the original describer. The color of the medusae while still attached in 
 specimens preserved in formalin is light salmon. 
 
 Found growing on a live gasteropod, Ilyanassa. Collected near 
 Woods Hole by Mr. Waldron. Type from Cold Spring Harbor, L. I. 
 
 Turris vesicaria A. Ag. Fig. 87. 
 (North American Acalephse, p. 164.) 
 
 Bell dome-shaped, surmounted by a subglobular or subconical 
 body, which appears to be hollow. Tentacles numerous when full 
 grown, but one good-sized specimen, apparently almost mature, has 
 only 8. Each tentacle is dilated at the base into a tentacular bulb 
 that bears an eye-spot. Proboscis short, ending in four frilled mouth 
 arms. Ovaries, forming large complicated frills, extending down on 
 either side of the radial canals and connecting at their proximal ends. 
 Eadial canals 4, broad and with transverse strise and edges which 
 appear jagged or frayed out. 
 
 Colors. Ovaries and tentacular bulbs yellow. 
 
 Distribution. Woods Hole, Mass. (Vinal Edwards). 87. Turris resicaria A. Ag. 
 
 A. Lateral view of young. 
 
 K8 jTm7oj**As it nh'ii'iilit MK'r. 
 B. Lateral view of older specimen. 
 
 C. Ventral view of yonng. 
 
 Turritopsis nutricula McCrady. Fig. 88. 
 
 (Proc. Elliott. Soc. vol. I, No. 1, p. 127.) 
 
 Bell hemispherical ovoid, or sub-conical. Marginal tentacles varying in number according to age, 
 from 4 to 24 in specimens examined, and held somewhat stiffly, each with a tentacular bulb bearing an 
 eye-spot at its base. Proboscis not reaching to the bell opening, and ending in four small mouth 
 tentacles bearing distal clusters of nematocysts. The genital products are contained in four large oval 
 masses around the proximal part of the proboscis and reaching to the bases of the mouth-anna. 
 .Radial canals 4. Velum broad. 
 
 Colors. Eye-spota red. Distal part of ovaries bright lemon yellow. 
 
 Distribution. Naushon. (A. Agassis.) Woods Hole, Massachusetts. 
 
376 
 
 BULLETIN i'K THK I'MTKU STATES fis:i cuM.M I>SH>N. 
 
 Nemopsis bachei Ag. Fig. 89. 
 (MOm. Am. Acatl. *-i., IV, p. 289.) 
 
 Bell deep, ovoid, sometimes almost globular; thickness of bell substance greater than in most of 
 preceding species, making bell cavity proportionally small. Tentacles in 4 bunches, the middle pair in 
 each bunch being distinctly club-shaped 
 at ends. Proboscis short and small, end- 
 ing in 4 much-branched mouth-tentacles, 
 each ramification of which ends in an 
 oval group of nematocysts. Mouth-ten- 
 tacles highly retractile and not evident 
 when animal is disturbed. The bunchea 
 of marginal tentacles are borne on con- 
 spicuous swellings or pads at terminations 
 of the four radial canals, and each tentacle 
 has a black eye-spot above its base. 
 
 Qjlorx. Tentacular bulbs and ovaries 
 yellow. Ends of middle tentacles of each 
 bunch dark brown. 
 
 Dixfi'ihtitiuii. Nant'icket and Xau- 
 
 shon (A. Agaasiz), Newport, Vineyard w. Nemaphtadielt.Ag. 
 
 Sound, Buzzards Hay. A. A aense-bulb and gronp of tentacles (enlarged^. 
 
 Bougainvillia carolinensis (McCr.). Fig. 90. 
 ( fJij>j>oci'< .-HI rni-olhn /<,-/* McCr. Proe. Elliott Soc., vol. T, No. 1, p. lill.) 
 
 1'x'll subirldliular, thick. Marginal tentacles in four bunches, arising from marginal swellings 
 which are narrower and more pointed than in the preceding species. Tentacles all alike, with slightly 
 enlarged ends, and eye-spots over their bases. Proboscis slender, with four branched mouth-tentaclea 
 ending in nematocysl batteries. Radial canals, 4. 
 
 I'nliii-K. Tentacular bulbs red, edged with yellow. Proboscis red. 
 
 IHxli-'ihiilinii. Common in the \Voods Hole region. 
 
 90. BougatnvtlllacaroUne!Uls(lfcCr,).; (juv.). 91. Boayniiirillia tupcrciliaris Ag. 92. ifc;/a grata A. AS. 
 
 Bougainvillia superciliaris Ag. Fig. 91. 
 (Cont. Nat. Hist. u. S., vol. iv, p. 289.) 
 
 Bell sub-globular, very thick. Marginal tentacles in four pairs at birth, later in four bunches. 
 Tentacular bulbs and eye-spots as in the preceding species. Proboscis thick and heavy but not 
 reaching much more than half way to the bell opening, ending in four branched mouth-tentacles 
 terminating in nematocyst batteries. Radial canals, 4. 
 
 Colors. Marginal sense bodies orange red surrounded by yellow. Proboscis pale yellow, tinged 
 with red distally. 
 
 Distribution. yew-port, Rhode Island (Leidv). Woods Hole. 
 
in Hlll nb Till-. WttoD.s HULK 
 
 7T 
 
 Lizzia grata A. Ag. Fig. '- 
 
 (I'nic. Boston Sor. Xilt Hist, p. 100.) 
 
 Bell deep, sub-conical in outline, lower portion noticeably wider than upper. Marginal tentacles 
 in 8 clusters borne on marginal swellings, but without distinct eye-spot.-! at base of each tentacle. 
 Proboscis rather large, capable of being protruded nearly to bell opening, and ending in 4 mouth- 
 tentacles which are branched, but not so extensively as in preceding species. Radial canals, 4. 
 
 Colors. Marginal swellings deep orange brown. 
 
 Dintriliulton. Newport, Rhode Island. 
 
 Willia ornata MeCr. 
 
 I I 'roe. Elliott Soc., vol. I, No. 1, p. 149. ) 
 
 Bell sub-conical. Tentacles of adult 10, one to each branch 
 of the radial canals. 1'robnscis short, ending in 4 lobular 
 unbranched month- 
 tentacles armed with 
 nematocysts which 
 are not aggregated 
 into round batteries. 
 Ovaries forming 4 
 innssesaronnd proxi- 
 mal part of proboscis. 
 Radial canals 4, each 
 divided distally into 
 4 branches. lietween 
 each paimf tentacles 
 a superficial struc- 
 ture like a " knotted 
 chord " passes up- 
 ward on outside of 
 bell. Sense-bulbs 
 found at liases of 
 tentacles. 
 
 rrffi( iFftTftnMMrin 
 
 11 [itiHi flfl 
 
 ;f i ii r u i 
 
 I \1 
 
 B. 
 
 liiiliii-nl,il'i Mayer. A. Abornl view. H. I.aiiT;:] 
 
 t'lil'irx. Not described by McCrady or Agassi/. 
 
 l)lttril,'inn. liuz/.ards Hay, Naushon. (A.Ag. ) 
 
 I have not seen this species, and the above description is condensed from that of McCrady.' 
 
 Orchistoma tentaculata Mayer. 
 
 l linll. Mils. <'mir.y.< ml V'-l. xxxvll. Xo. 1. p. 3.) 
 
 I'.ell deep, cu;.-.-haped, its stilistance very thick in upper portion much reducing depth of bell 
 cavity. Marginal tentacles .'il', with sense-bulbs at their bases. No otocysts. Proboscis short, with 4 
 k>bulated mouth-arms, the lobes margined witli nematocyst bearing tentacles. Radial canals 10, 
 alternating with Hi short tube- given off from near top of bell cavity. Ovaries borne on proboscis. 
 
 Colors. Prob iscis and sense-bulbs red. 
 
 l>i.ili-!lnil!(iii. Newport, Rhode Island. 
 
 Sutima limpida V Ag. 
 
 (North Anicni-.ill AculeplKi'. |i. IKi.l 
 
 Like I-', niii-n with the following exceptions: P>a.es of the four tentacles not swollen, and each 
 provided with two lateral cirri. The ovaries, tentacles, and prolxiscis almost co 
 l>ixl,i ! ,i:ln)n. liu/./ards i'jy: N'aushon. (A. Ag. ) 
 
378 
 
 BULLETIN OF THE UNITED STATES FISH COMMISSION. 
 
 Eutima mira McC'r. Fig. 93. 
 (Proc. Elliott Soc., vol. I, No. 1, p. 190.) 
 
 Bell broad, sub-conical, the lateral profile sinuous, upper part dome-shaped. Tentacles 4, with 
 swollen sense-bodies at bases, but without lateral cirri. Otocysts 8, two between each two radial canals, 
 
 conspicuous, containing highly refractile granules. A number of 
 rudimentary tentacles around the bell margin. Proboscis very 
 long, extending below the bell two or three times the depth of 
 the latter, and ending in a mouth surrounded by a disk-like lobed 
 frill. Ovaries disposed along the radial canals. 
 
 Colors. Swollen tentacular bases a bright light green. Ova- 
 ries whitish. Proboscis not noticeably colored. 
 
 Distriliiitliin. Woods Hole, Massachusetts. August 10, 1899. 
 
 Hebella 'calcarata (A. Ag.)=.I>ynamena cornicina McCr. (in 
 
 part). Fig. 94. 
 I Liiiulirra nilramta Ag., Cont. Nat. Hist. U. S., p. 360.) 
 
 Bell of "adult rather shallow, bowl-shaped, young almost 
 spherical, with the outline of the sides rather sinuous. Marginal 
 tentacles rather numerous, hollow, with sense-bulbs at their 
 bases, r and a spur-like projection extending inward from the base 
 of each. Other tentacles have no sense-bulbs and are much more 
 slender, appearing like lateral cirri in young specimens; still 
 other tentacles are short and clavate. Proboscis very short, ending in four frilled mouth-arms* 
 Ovaries in form of convoluted bands along the four radial canals. 
 
 Colors. Ovaries and larger tentacles dark yellowish. Eye-spots dark violet. (A. Ag. ) 
 Diati'lbiition. Vineyard Sound (Verrill); Newport ami Woods Hole. Xaushon. (A. Ag.-) 
 
 93. EutitHtt r/u'rri MeOr. 
 
 94. Hebella caicarata (Ag.). 
 
 95. EuHii-ilfitiiiiiiiiiln'rianlisA.Ag. A. tatiirul viow. B. (mil view. 
 
 Eucheilota ventricularis McCr. 
 (Proc. Elliott Soo., vol. I, No. 1, p. 187.) 
 
 Bell hemispherical. Tentacles 16 to 20, with sense-bulbs at bases, highly contractile. Otocysts 8, 
 with refractile granules arranged in an arc. Proboscis short, tubular, not reaching to bell opening. 
 Eadial canals 4, wide. Ovaries occupying whole length of radial tubes. Velum wide. 
 
 Colors. Proboscis yellow, with a red central portion. Ovaries yellow, sense-bulbs with a red 
 center. 
 
 XKitribulion. Naushon; Buzzards Bay (A. Ag.). 
 
m DBOID Oi i HI \\ OOD HOLE REGION. 
 
 379 
 
 The above description is condensed from that of McCrady. Dr. Agassiz appears to doubt whether 
 his species is the same as that of McCrady, and describes it as having lateral cirri to the tentacles. I 
 have not seen this species. 
 
 Eucheilota duodecemalis A. Ag. Fig. !)5. 
 (Cent. Nat. Hist. U. S., iv, p. 35:i.) 
 
 Bell hemispherical or sub-globular. Marginal tentacles -), each with a sense-bulb and two lateral 
 cirri at its base. Three otoliths between each two tentacles, making twelve in all. Proboscis very 
 short, tubular, with inconspicuous lips. Ovaries along radial canals, very conspicuous when mature. 
 Radial canals 4. Velum broad. 
 
 Colors. Spots on sense-bulbs straw-yellow. 
 
 Distribution. Buzzards Bay (A. Ag. ); Newport; Woods Hole. 
 
 Clytia noliformis (McCr. ). 
 
 ( f.'aii/pft/Kifaria uttlifai'iitit ^k('r.. Proc. Elliott Soc., vol. I, No. 1, p. 194.) 
 
 Bell hemispherical. Marginal tentacles 4 in young, and more numerous in adults. Otocysts 8, 
 two between each two radial canals; always between tentacle bases, and not on them. No eye-spots. 
 Proboscis very short, ending in a four-lobed mouth. Radial canals 4. 
 
 CiJ'ifis. There arc no conspicuous colors. Ovaries yellowish-white. 
 
 Di-li-ilintioii. Buzzards Bay and Xaushon (A. Agassiz, under name of Plfity/ii/j-ia ri/lin<lrii-a) . 
 
 Clytia bicophora Ag. 
 
 (Cent. Nut. Hist. U. ,S., vol. iv, p. 3<H.) 
 
 Bell hemispherical, considerably flattened in older specimens. Tentacles 4 to 16, according to 
 age. Otoliths 8 or 16, according to age, placed between tentacular bases. Proboscis short, ending in a 
 4-lobed mouth. Ovaries, in adult, reaching along radial canals nearly to proboscis. Radial canals 4. 
 
 > ../,,, -<. Ovaries brown. Black spots on swollen bases of tentacles. 
 
 Dinlrilmtion. Naushon; Vineyard Sound (A. Ag.). 
 
 I have not seen this species, and the above description is condensed from that given by Dr. A. 
 Agassiz, North American Aralepha 1 , p. "8. 
 
 9T. Til/Ill I'oi-ul 
 
 97. itbili'ii riiniiitittin-itli* McCr. 
 
 Tima formosa Ag. Fig. 96. 
 
 (Com. Nut. Hist. U. fi., vol. IV, p. 362.) 
 
 Bell broadly campanulate, the edges perceptibly flaring, the lateral outline sinuous. Marginal 
 tentacles 32, some of which are often rudimentary, with swollen sense-bulbs at their bases. Otocysts 
 numerous, placed between the bases of the tentacles, each with a few granules near its margin. 
 Proboscis very long, in the shape of a very attenuate cone with its base upward, and extending far 
 beyond the bell opening when expanded. Mouth surrounded by four conspicuous frilled lappets. 
 Ovaries strongly convoluted and extending the full length of radial canals and proboscis. Radial 
 canals 4. Size very large. Among the largest of our hydroid medusa;. 
 
 Colon. Ovaries and sense-bulbs whitish; sometimes light-yellowish. 
 
 Digtrilvtion. Woods Hole (F. M. Walmsley); Vineyard Sound (Verrill). 
 
380 I-.!'!.!,;: TIN <>K THK TNITKI) STATUS nsii COMMIS:"*] 
 
 Obelia commissuralis MrCr. Fig. n". 
 
 tl'roo. ElliotI Soc.. vol. I. No. 1. p. l'J7.) 
 
 Bell disk-shaped. Marginal tentacles l(i at time of liberation, long and slender. Ovaries not 
 developed at time of liberation. 
 
 D:*trilnit:-i. . < o'.ouiea abundant in Wood.- Hole region, '.'rowing on piling of wharves and on 
 siibm'-r-rd timb.Ts gi aenilly. 
 
 Obelia freniculata (I. inn.). Figs. ISdA, !!S. 
 
 I S,':' ! '',''!f : " >, ::ii'u!<tti.l Linn.. Syst. Nitt.. p. HI'-'. I 
 
 Bell disk-shaped, or shallow bowl-shaped. Marginal tenta- 
 cles LM at birth, each with an inward projei ting .--pur. Otoliths 8, 
 two bet we, 'ii each two radial canals, placed over the liases of the 
 tentacles and not between them. Proboscis short, with four 
 inconspicuous lobi'Jar lips. Radial canals 4. Ovaries oval, hang- 
 ing beneath the middle portion of the radial canals. No sense- 
 bulbs. Thi", like other species of Ohel'm, has the habit of swimming vvith the bell reversed, so that it 
 appears somewhat like an umbrella turned wrong side out. 
 
 Co/or.--. ---The only color is in the light-yellowish ovaries ami proboscis. 
 
 Jlixli'Hiiitinii. Abundant throughout Wood.- Hole region. 
 
 Obelia loiigissima ( Pallas i. 
 
 >, fnfnrin //^//s.W;//(i I 'a lla^. KlrMrlitis Zoopliytoruni, p. 1 1'.'. ) 
 
 It isexceedinglv ditiicult, if not impossible, to differentiate the medusa' of the various species of 
 this genus. In sonr.' cases the only way to identify them is to see them given off from the hydroid 
 colonies. I know of no means of distinguishing this species from the preceding except that the ten- 
 tacles may be 20 instead of '24. 
 
 IHsti'lbii'inii. The hvdroid colonies have been found at Woods Hole and off <iay Mead. 
 
 Obelia flabellata (Winers) 1 Eueope polygenA A. Ag.?- 
 
 Ann. anil MK. Nut. Hist.. :ld srrirs. vol. xvm. p. '7. -'North American Acalrplui. I 
 
 lliffers from the preceding in no constant feature that I am aware of. 
 Dixlr'ilnitiuii. Woods Hole; off Thimble Island (Verrill). 
 
 Obelia gelatinosa (Pallas) l = //i/(;ifin i/ii/miti'n A. Ag.'-' (Verrill). 
 (> frrtuldi-ia yrlittiiiHtn 1'illlns. Elunchii" Zoopliytorinn. p. llci. ^Xortli Anirric'all Aralrph;r. p. 94.) 
 
 Bell disk-shaped. Tentacles 16 at time of liberation, each with an inward-projecting spur. 
 Otocysts 8, placed over bases of tentacles. Proboscis short, with mouth surrounded by four tabular 
 lips or mouth-arms. Radial canals 4. Ovaries round, hanging beneath middle part of radial canals. 
 
 Otlor*. Ovaries and proboscis light-yellowish. 
 
 Jtixtribiition. Colonies have been found growing at Xew Haven, Conn.; along the Rhode Island 
 coast, and in Vineyard Sound. 
 
 Obelia dichotoma (Linn.). 
 
 (Sniiilin-iu ilicliiilniiiii l.inn., Syst. Nut., p. 131'i> 
 
 Bell very shallow, disk-shaped. Marginal tentacles 16 at time of 
 liberation. Not distinguishable from the preceding. 
 
 Distribution. Colonies dredged off Gay Head, 1 fathom (Verrill). 
 
 Oceania singularis Mayer. 
 
 (Bull. Mus. Comp. Zool., vol. xxxvin, No. 1, p. 7. ) 
 99. Oceania singulars Mayer. 
 
 Bell rather shallow, flaring decidedly at margin, and with a well 
 
 marked dome-shaped apical projection. Marginal tentacles 16, each bearing a sense-bulb at ita base. 
 There are rudimentary tentacles between bases of larger ones. Proboscis not extending beyond 
 velum, and ending in four broad lobes or mouth-arms that are not fimbriated. Eadial canals 4, bear- 
 ing the ovaries on their upper portion. There is an otocyst between each pair of tentacles, including 
 the rudimentary ones. 
 
HYDROIDS OF THE WOODS HOLE REGION. 
 
 381 
 
 Colors. "The entoderm of the proximal part of each tentacle bulb is turquoise-green, and the 
 distal part is brownish-red. The entoderm of the proboscis and of the radial tubes in the neighbor- 
 hood of the gonads is of a delicate turquoise tinge." (Mayer.) 
 
 Distribution. Newport, R. I. Dr. Mayer kindly allowed me to sketch the type. 
 
 Tiaropsis diademata Ag. Fig. 100. 
 (Memoirs Ainer. Acad., vol. iv, p. 289. ) 
 
 Bell hemispherical in adult, ovoid in young. Marginal tentacles numerous, with swollen sense- 
 bulbs at the bases of the larger ones. Otocysts 8, situated between the bases of the tentacles and each 
 containing a central dark dot with an arched row of refractile granules. Proboscis short, not reaching 
 much more thanjhalf way to the velum, and ending in four conspicuous, extensively frilled or fimbriated 
 oral arms. Radial canals 4. Ovaries long, extending nearly to the circular canal. 
 
 Colors. Specimens in formalin have the ovaries, oral arms, and tentacle bases light green. 
 
 Dixtriliutifm. Woods Hole, Mass. (Collected by Mr. Vinal Edwards.) 
 
 A. 
 
 A. Otooyst (enlarged). 
 
 101. Epenthcsit fvlleata SIcCr. 
 A. Details of margin, o. Otocyst. s. Sense bulb. 
 
 Epenthesis folleata McCr. Fig. 101. 
 (I'roc. Elliott Soc., vol. I, No. 1, p. 191.) 
 
 Bell hemispherical, with thin walls. Marginal tentacles numerous, with sense-bulbs at bases. 
 Otocysts alternating with tentacle bases. Proboscis short, ending in 4 lobular mouth-arms. Ovariea 
 4, round, hanging from under radial canals nearer to margin than to proboscis. Radial canals 4. 
 
 Color*. Proboscis light green. Tentacular bulbs red. 
 
 Dintrlliiitiini. Newport, Rhode Island. 
 
 Trachynema digitale A. Ag. Fig. 102. 
 (Xorth American Acalephse, p. 57.) 
 
 Bell very deep, with an outline something like that of a bishop's miter, somewhat pointed above; 
 Marginal tentacles numerous, but most of them are usually lacking in preserved specimens. Otocysta 
 4, according to Agassiz, but they seem to be lacking in the specimens (males) that I have examined. 
 Proboscis long, reaching nearly to the velum, ending in a constricted portion bearing the mouth 
 surrounded by four lobular or finger-like mouth-arms. Radial canals 8. OvarieslS, long "sausage- 
 like" organs, reaching sometimes halfway from the upper part of the bell cavity to the velum. Velum 
 wide, strong, extensively wrinkled. 
 
 Colors. Bell slightly pinkish. Contracted tentacles crimson at their extremity. Ovaries milky. 
 Otocysts garnet-colored. (A. Agassiz. ) 
 
 Distribution,. Newport, Rhode Island. Woods Hole. (Vinal Edwards. ) 
 
382 
 
 BULLETIN OK THK UNITED STATES FISH COMMISSION. 
 Gonionemus vertens A. Ag. Fig. 103. 
 
 (Com. Nut. Hist. C.S., iv. p. 350.) 
 
 Bell hemispherical. Marginal tentacles numerous, each with a sense-bulb at its base, and a 
 "knee-pad" of adhesive cells near its end which appear as thickenings of the tentacles at a short 
 distance from their ends. Otocysts numerous between the bases of the tentacle.". Proboscis short, 
 not reaching more than halfway to the velum, and ending in four frilled mouth-arms. Radial canals, 4. 
 Ovaries 4, forming convoluted bands fallowing the radial canals to the bell margin. 
 
 Color*. Tentacle bases emerald green and brown, with a black eye-spot. Proboscis and ovaries 
 yellowish brown. 
 
 Dixt.riliiitioH.The Eel Pond, at Woods Hole. 
 
 Melicertum campanula Kscli. 
 
 (Syst. dt-r Ami., p. 105.) 
 
 Fig. 104. 
 
 Bell deep, the upper portion somewhat narrowed. Marginal tentacles numerous, hollow, with- 
 out eye-spots at their liases. Nootocysts. Proboscis short, ending in eight frilled mouth-arms. Radial 
 canals 8. Ovaries 8, convoluted, extending beneath the radial canals to the margin. 
 
 ('tilrirx. Ovaries, proboscis, and tentacle bases light yellow. 
 
 Dinli-iliiilinii. Woods Hole. (Vinal Edwards.) 
 
 102. TV"-'// '/"""" 
 , Kubr.). 
 
 .ffiquorea albida A. Ag. 
 (North American Aealephse, p. 110.) 
 
 Bell rather shallow, in the shape of a low dome with lateral outlines slightly sinuous. Marginal 
 tentacles very numerous, with otocysts between their bases and without evident sense-bulbs. Pro- 
 boscis small, butjevident, without mouth-arms. Radial canals very numerous. 
 
 Colors. Radial canals appearing as whitish lines. 
 
 Distribution. Buzzards Bay; Naushon. (A. Agassiz. ) 
 
 I have not seen this species, and the above description is taken from that of the original describer. 
 
 Zygodactyla grcenlandica Ag. 
 (Cont. Nat. Hist. U.S., vol. IV, p. 360.) 
 
 Bell shallow, a low dome, hardly emarginate along the lateral outlines. Marginal tentacles 
 exceedingly numerous, swollen at their bases. Otoeysta numerous; situated between the tentacle 
 bases. Proboscis large, thin-walled, reaching beyond the bell opening when not retracted, and sur- 
 
 1 Since the above was written numerous specimens of this species have been secured at Woods Hole by Mr. Hal. Childs. 
 
MYDUOIDS 01- THK WOODS HoI.K 
 
 rounded by extensively i' rilled or liiulirmU'd month-arms. Hadial canals and ovaries exceedingly 
 numerous, the latter extending almost to the margin. Size very large. 
 
 Colon. Not given by the original deseriber. 
 
 I have not M'i'i! I hi- 1 "fiecics. and condense the description from that of Or. A. AgMBUE. 
 
 Bhegmatodes tenuis A. Ag. Fig. 105. 
 (North Amerii'iin Ai'ak'jilia', p.9.">.) 
 
 Bell very shallow, disk-shaped, with a central elevated portion. 
 Tentacles very numerous, slender. Otocysts numerous, situated between 
 the tentacle bases. There is practically no proboscis, but an irregular 
 aperture under the center of the bell surrounded by an irregularly 
 striated membrane which forms the floor of the digestive cavity. 
 Kadial canals numerous, there being about 32 in specimen examined. 
 Ovaries linear, numerous, reaching along the radial canals from the 
 digestive cavity nearly to the margin of the bell. 
 
 ?L1\'. W<*V1LV liC^l 1J l*J IMf^ i*M.igt* vji. i.'^ -j 
 
 CoZors.-There is very little coloration about this species. The 105 A. Oral view of center of d 
 
 ovaries are pale yellowish or brownish. 
 
 Distribution. Naushon (A. Agassiz). .Woods Hole. 
 
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