RICHAED H, STRETCH 
 
ZooUdept. 
 
 BIOLOGY 
 UBRARY 
 
PI.VHL 
 
DESCRIPTIVE MANUAL 
 
 BRITISH LAND 
 
 FRESH-WATER SHELLS 
 
 CONTAINING 
 
 DESCRIPTIONS AND FIGURES OF ALL THE SPECIES, 
 
 BY DIXON AND WATSON. 
 il 
 
 PRINTED FOR DIXON " ^ AND\WAT*C'U, ' 
 
 DAEL1NGTON: 
 HARRISON PENNEY, PRINTER, PREBEND ROW. 
 
 1858. 
 

 OGY 
 LIBRARY 
 G 
 
PREFACE. 
 
 IT is to be regretted that the study of oue of the most 
 pleasing, and, at the same time, most accessible natural his- 
 tory pursuits the Land and Fresh-water Mollusks of our 
 island is so much neglected. True, it is, that they are 
 surpassed, both in size and beauty of colouring, by their 
 brethren of the ocean, and for that reason, perhaps, have 
 been overlooked by many - yet there are among these little 
 gems of nature, such beautiful forms, and delicate conforma- 
 tions, that they soon arrest the attention and interest of 
 those, who once commence either to collect or study them. 
 
 We believe this branch of natural history will, some day, 
 become much more popular than it is at present. It has 
 many claims upon those who are desirous of becoming 
 acquainted with the varied forms of created life, which 
 nature presents to our view. Perhaps the foremost of 
 these claims, is the fact, that wherever we go, whether it be 
 in the most luxuriant woods, or upon the bleak hills ; we 
 have but to look around us, among the herbage, in the 
 waters, or even under the stones which lie at our feet, and 
 some one or other, in all probabilit} r several, of these little 
 creatures may be found. In one wood, within the compass 
 of a few square yards, as many as twenty different species 
 have been found. 
 
 To the young it especially recommends itself, on account 
 of the limited number of species which our island produces, 
 thus enabling any one, with a little interchange, to form 
 almost a complete collection, in a small compass ; and 
 offering a good stepping-stone to the study of nature in its 
 more extended forms, and complicated relations. Having 
 
 252045 
 
IV. PREFACE. 
 
 had our lot cast in a district in which the Land and Fresh- 
 water shells abound, perhaps more plentifully than in any- 
 other part of the kingdom ; and having noticed the never 
 failing source of pleasure, the collecting, examining, naming, . 
 and arranging of them has yielded to young persons under 
 our care, we have often urged the principals of other 
 schools to introduce the study among their pupils ; knowing 
 well, that when once an acquaintance is formed with them, 
 such is their simple elegance, that they constantly improve 
 in appearance as the acquaintance becomes more intimate, 
 and it will be found, that few who have once begun will 
 be inclined to give up, till the whole subject has been 
 mastered. 
 
 But here a difficulty has arisen, a difficulty which we 
 hope, in some degree, the present little volume will remedy ; 
 all works on natural history are expensive, and even the 
 simplest complete works on Land and Fresh-water Shells, 
 do not form an exception to the rule. This has induced 
 many to stumble at the threshold of the science. That 
 one volume in a school may enable most of the elder boys 
 to name what they have collected, we admit ; but these 
 mostly give up the study, when they return to their 
 respective homes, for want of a descriptive manual, and 
 such as do persevere, have to trouble their friends to name 
 any species they may not have previously met with. 
 
 These considerations, and the earnest request of many 
 of our valued friends and correspondents, in various parts 
 of the kingdom, have induced us to undertake the present 
 work ; which will be found to contain complete descriptions 
 of all the species, and other matter of a suggestive and 
 practical nature, which' the experience of several years has 
 enabled us to furnish. 
 
 North of England Agricultural School, 
 Great Autov. 
 
INTRODUCTION. 
 
 THOUGH we do not wish to add to the bulk of the 
 present little volume, we think a few explanatory 
 remarks needful to enable the young chonchologist, 
 to proceed easily in the pursuit of these interesting 
 objects of study. 
 
 We have followed the nomenclature adopted by 
 Prof. E. Forbes and S. Hanley, in their magnificent 
 work " British Mollusca," the names there used being 
 those under which the species were first specifically 
 described. Those who are acquainted with this valu- 
 able work, will find in many places, we have adopted 
 the same observations, though somewhat condensed, 
 particularly as regards the external form and structure 
 of the animals, some of which we have not had the 
 opportunity of observing. On disputed points we 
 have generally taken the opinion of the "most noted 
 conchologists, without entering into detail ; but, when- 
 ever practicable, and that has been almost always the 
 case, before adopting the remark of any author, we 
 have taken care that the same has been confirmed by 
 our own observations. 
 
 With the expectation of this little compilation 
 falling principally into the hands of young persons, 
 or those just commencing the study of conchology in 
 this limited department, we have tried to adjust our 
 remarks to such ; we have been particularly careful to 
 
VI. INTRODUCTION. 
 
 point out species that could possibly be confused, 
 noting their characteristic points in contradistinction 
 to those of their nearest allies ; we have also generally 
 given not only the locality, but also the circumstances 
 under which each may be found, together with other 
 matter which the experience of several years of col- 
 lecting, has enabled us to furnish. To the many 
 localities we have gathered from various works, we 
 have added a number which now appear for the first 
 time in print, these, we hope, will prove a valuable 
 addition. 
 
 It will be noticed that most of our British species 
 are widely distributed ; in almost any district, a radius 
 of a few miles, will supply about three-fourths of the 
 whole number ; so that any one, without assistance or 
 exchange, can possess himself of a tolerably large 
 collection. A few, however, seem confined to the 
 Southern and Midland Counties, while one or two 
 are seldom found except in the North : among the 
 former are Assiminia Grayana, Testacella halio- 
 toidea, Helix aperta, Helix pomatia, Helix pisana, 
 Helix Carthusiana, Helix obvoluta, Helix revelata, 
 Bulimus acutus, Bulimus Lachamensis , Clausilia 
 biplicata, and Succinea oblonga ; among the latter are 
 Zonites excavatus, Zonites purus, Helix hybrida, 
 Helix sericea, Helix fusca, Helix limbata, Clausilia 
 dubia, Pupa Anglica, Limnceus Burnetti, Plan- 
 orbis nautileus, and Acme lineata. There can be 
 little doubt that Geological formation plays an im- 
 portant part in the distribution of land shells, and 
 for this reason, probably, the southern part of our 
 island produces many species which are seldom, some 
 never, found further north. This is principally owing 
 
INTRODUCTION. Vll. 
 
 to the calcareous nature of the rocks. Helix aperta 
 and Testacella haliotoidia have been found only in the 
 Channel Islands, and would, on that account, be erased 
 from the British faiina, by some naturalists. 
 
 The implements required for carrying on the study 
 are few, simple, and not expensive. A SPOON, for 
 scooping-up the water varieties from amongst aquatic 
 plants, which can be made of tin, with fine gauze 
 wire or perforated zinc at the bottom, the gauze must 
 be so fine that it will not allow the smaller Pisidia, fyc. 
 to pass through ; to this a handle five or six feet in 
 length may be attached, or it is often convenient to 
 have it to fix on the end of a walking stick. BOXES, 
 of various sizes, to keep the finer varieties from being 
 broken, and to separate those found in different locali- 
 ties. With these and a small POCKET MICROSCOPE, 
 the conchologist may consider himself fully equipped. 
 
 After having collected a considerable number of 
 shells, our first care is to kill the mollusks which 
 inhabit them ; this is most speedily and effectually 
 accomplished by pouring boiling water upon them; 
 we then disengage them by means of a needle, fastened 
 to a small handle, or perhaps occasionally use a crooked 
 pin. The very small ones need no cleaning. Our 
 next care should be to have them properly mounted : 
 this of course must depend almost entirely on the taste 
 of the collector. We have found a mahogany box or 
 case, eighteen inches square, and two inches in depth, 
 so made that the top and bottom are of equal depth, 
 the best suited for displaying the whole collection at 
 one view. The shells are attached by gum or glue 
 to the top as well as the bottom of the case. After 
 the inside has been papered out, the names, neatly 
 
Till. INTRODUCTION. 
 
 cut from a printed catalogue, should be arranged in 
 columns, taking care to have sufficient room for the 
 shells, and thus, by a little contrivance, the names 
 of the whole of the species may be made exactly to 
 fill the case. Above the names several specimens of 
 as many kinds as you are possessed of should be fast- 
 ened ; the remainder can be added from time to time, 
 as you are able to meet with them. Boys will find 
 this an excellent plan. For cabinets they are, perhaps, 
 best mounted on separate pieces of wood, with the 
 labels, synonyms, locality, &c. attached. There is an 
 advantage in this latter plan, the specimens can be 
 lifted so as to be more closely examined or even placed 
 under a microscope. Some prefer keeping them in 
 small pill boxes, with the label outside, this plan, too, 
 has its advantages. 
 
 We would advise those who are collecting, to obtain 
 more individuals of any species than they want, espe- 
 cially of those that are somewhat rare and local; that 
 so they may have the means of exchanging for others, 
 which they may be in want of. 
 
 We have not thought it worth while to burden our 
 pages, with even giving the names of species which 
 have been erroneously introduced into the British 
 Fanna, with the exception of one or two which have 
 found their way into almost every collection, and some 
 which are almost acclimatized. H. aperta, which ap- 
 pears in all works on British Conchology, is retained, 
 though not strictly British. One or two shells which 
 are now and then found amongst the debris of rocks 
 or in superficial deposits may be considered as sub- 
 fossil. In this state we have found, among others, 
 Succineo oblonqa. Zua lubrica, Bithinia tentaculata, 
 
INTRODUCTION. IX. 
 
 Valvata piscinalis, Achatina acicula, Pupa Venetzii. 
 The species found in the older series differ from the 
 recent British Land and Fresh-water Mollusks in being 
 considerably larger, and are more nearly allied to our 
 present tropical species. Had our limits allowed of it, 
 we should have somewhat enlarged our observations 
 on Geological distribution, a branch which has hitherto 
 been overlooked. It would be advisable for readers 
 in different parts of the country, to record in some 
 of our Natural History publications, not only lists of 
 shells found in the district in which they live, but also 
 the circumstances under which they are found, the 
 formation of the rock, or the nature of the water, &c. 
 We append a few of the many works that can be 
 consulted, by those who are desirous of further in- 
 formation respecting the structure, organization, &c. 
 of these little creatures, than the object of the present 
 work will allow. At the same time we would advise 
 our younger readers to make their own observations 
 and compare them with those of others, rather than 
 learn from works of art what can only be properly 
 acquired by an inspection of nature herself. What 
 could afford more delight than to make the Fresh- 
 water varieties the inmates of vivariums, where their 
 peculiarities could be watched day by day, or to colo- 
 nize our neighbouring woods and hedgerows with some 
 of the land species ! 
 
 In the wonderful structure and development, as well 
 as the habits of mollusks, there are many peculiarities 
 that are common to all, so that to the reflecting student 
 a thorough investigation of a few of the commoner 
 species, may furnish him with a vast amount of in- 
 formation. 
 
X. INTRODUCTION. 
 
 A HISTORY OF BRITISH MOLLUSC A AND THEIR 
 
 SHELLS ; Professor Edward Forbes and Silvanus 
 
 Hanley. 
 A MANUAL OF LAND AND FRESH-\VATEU SHELLS 
 
 OF THE ' BRITISH ISLANDS ; William Turton, 
 
 revised and much enlarged by John Edward Grey. 
 ILLUSTRATIONS OF BRITISH CONCHOLOGY ; Thomas 
 
 Brown. 
 
 TESTACEA BRITANNICA ; George Montague. 
 HISTORIA VERMIUM TERRESTRIUM ET FLUVIATILIUM; 
 
 O. F. Muller. 
 CATALOGUE DES MOLLUSQUE TERRESTRIS ET FLUVI- 
 
 ATILLS DU PAS DE CALAIS ; Bouchard Chantreux. 
 
BRITISH LAND AND FRESH WATER SHELLS. 
 
 Naturalists have divided all living, sentient beings, 
 into four sub-kingdoms, according to the different types 
 upon which they are constructed, viz., 
 SUB-KINGDOM. I. VERTEBRATA backboned animals. 
 II. MOLLUSC A soft or pulpy animals. 
 " III. ARTICULATA jointed animals. 
 
 IV. RADIATA rayed, or branched 
 
 animals. 
 
 The animals under consideration in the present vo- 
 lume, belong to Mollusca, the second sub-kingdom, 
 which is divided into the following six classes : 
 CLASS I. CEPHALOPODA head-footed, as cuttle fish. 
 " II. GASTEROPODA stomach-footed, as common 
 snail. 
 
 III. PTEROPODA wing, or fin-footed, ashyalsea. 
 
 IV. BRACHIOPODA arm-footed, as terebratula. 
 " V. CONCHIFERA shell-bearers, as all bivalves. 
 
 VI. TUNICATA membrane-covered, porophora. 
 
 The two classes, Gasteropoda and Conchifera, em- 
 brace all the land and fluviatile species. 
 
 Commencing at the foot of the scale, the bivalve shells 
 will come first under notice. 
 
 CLASS V. CONCHIFERA. 
 SECTION I. ACEPHALA LAMELLIBRANCHIATA. 
 
 So called from the animal having no head, and its 
 breathing apparatus being expanded into laminae. The 
 mouth is situated between the four leaflets of the bran- 
 chia, with a central foot more or less distinct, and com- 
 pressed, covered by two pair of leaf-like gills, and large 
 
CONCHIFERA. 
 
 leaf-like mantle. The respiratory organs, though with- 
 in the mantle, are free from it. The two valves of the 
 shell, which protect the animal, are moulded on, and 
 secreted by. the mantle. These valves are united at the 
 back by a ligament, which causes them to expand, and 
 they are drawn together by an adductor muscle attached 
 to the inner surface of each shell. So simple is the 
 construction of the animals that the dissection of a few 
 individuals will convey more knowledge than a volume 
 of explanation. 
 
 In this section, only three tribes inhabit the fresh 
 waters of this country. 
 
 TRIBE I. CYCLADID^E. 
 
 Animal With front part of the mantle open and plain at the 
 edge ; tube of the siphon produced, and either partially 
 separated from their unfringed extremities, or completely 
 united to them. Foot large, and tongue-shaped. 
 
 Shell Thin, rather swelling, nearly equal, striated and fur- 
 rowed, covered by an epidermis, ligament outside, hinge 
 with lateral and cardinal teeth. All the British species 
 are ovoviviparous. This tribe is divided into two genera 
 Cyclas and Pisidium. 
 
 TRIBE II. UNIONIDJE. 
 
 Animal With margins of mantle incapable of being reflexed, 
 freely open almost the entire length ; a difference in the 
 structure of their hinder borders alone indicates the siphon- 
 tubes ; short cirrhi in the branchial region ; foot large, 
 broad, compressed. 
 
 Shell Equivalve: covered with an epidermis ; hinge with or 
 without teeth ; ligament external. It includes two genera 
 Unio and Anodonta. 
 
 TRIBE III. MYTILID^E. 
 
 Animal With edges of mantle united all round except three 
 apertures, one below for the passage of a short strap- 
 shaped foot, with a byssus at the base, and a distinct 
 byssal groove, and two behind ; the upper one a hole only, 
 and the lower one produced into a siphon ; mouth large 
 and reflexed. 
 
GASTEROPODA. O 
 
 Shell Almost triangular; regular; inequilateral ; liinge de- 
 void of teeth ; ligament linear, internal. It includes 
 only one genus Dreissena. 
 
 The Univalves come next under notice. 
 
 CLASS II. GASTEROPODA. 
 SECTION I. GASTEROPODA PROSOBRANCHIATA. 
 
 So called from the animal moving on its stomach and 
 having its organs of breathing in advance of the head. 
 The mouth is usually at the end of a short proboscis, 
 with two tentacles ; eyes either placed at the hinder 
 edge of the tentacles, on a separate pedicel, or sessile, at 
 their base ; branchia pectinated, or plume-like, in the 
 form of one or more extended filaments, through which 
 they respire the air of the water ; the mantle in which 
 the excretory orifices are placed, is entire, and without 
 syphon, forming a receptacle for the breathing organs 
 in the shape of a vaulted chamber over the head ; ab- 
 domen well developed : sexes distinct. The shell, pro- 
 tecting partly the gills, and partly the other parts of the 
 body, is spiral, with the mouth either entirely round, 
 or half-moon shaped, covered when the animal has re- 
 tired within its shell, with a horny operculum variously 
 shaped. 
 
 In this section there are three tribes found in our 
 fresh waters. 
 
 TRIBE I. NERITID^E. 
 
 Animal With mouth semiovate ; tentaculce slender, awl- 
 shaped ; eyes on prominent pedicels, at the hinder edge 
 of the tentacles ; foot rather short, oblong, triangular ; 
 tongue complicated in its structure, and denticulated; 
 sides of the body simple. 
 
 Shell Thick, semi-globose, imperforate ; spire with a few 
 whorls only, last whorl very large and expanded ; outer 
 lip acute ; columella flattened ; surface covered with an 
 epidermis ; the operculum, which is spiral and has a tooth 
 at the lower edge, just Jits the semi-ovate mouth of the 
 shell to which it is attached by two internal processes, 
 B 2 
 
GASTEROPODA. 
 
 forming a hinge on the inner lip, making this genus the 
 connecting link between the univalve and bivalve shells. 
 It contains only one genus Neritina. 
 
 TRIBE II. PALTJDINIDJE. 
 
 Animal With a lengthened broad ovate mouth ; head bear- 
 ing two tentaculce, which are long, slender, and setaceous 
 at their tips ; at the outside of their base, the pedicels 
 on which the eyes are placed subtend; gills single, enclosed; 
 tongue very short with a series of transverse denticles ; 
 foot triangularly oblong, bearing on a rounded lobe the 
 operculum. Bisexual. Male organ in the right tentacle, 
 causing these tentacles to be of unequal length in the 
 males. % 
 
 Shell Conical or turbinated, with a produced spire, covered 
 with a coloured epidermis ; mouth ovate or nearly round; 
 peristome thin, entire; operculum corneous, with a nucleus 
 at the centre expanding in concentric rings. This tribe 
 contains three genera Paludina, Bithinia, and Valvata. 
 
 TRIBE III. LITTORINID^. 
 
 Animal With elongated trunk ; head muzzle-shaped, bearing 
 two rather short subulate tentaculce ; the eyes sessile 
 on the outerside of their bases ; no lobes on neck ; the 
 lobe of the operculum without filamentary process; tongue 
 with dissimilar lateral elements armedwith incurved teeth; 
 foot rounded at both ends. 
 
 Shell Solid, turbinate, spire produced ; mouth ovate not con- 
 tinued; lip of columella oppressed; outer lip with sharp 
 edge; operculum corneous, fitting the mouth of the shell, 
 formed spirally by a few rapidly increasing whorls. It 
 includes one genus Assiminia. 
 
 SECTION II. GASTEROPODA PULMONIFERA. 
 
 So called from their moving on their stomachs, and 
 bearing lungs enabling them to breathe the atmosphere. 
 It embraces all the terrestrial mollusca, and the majority 
 of the gasteropods inhabiting fresh water. They are 
 furnished with pulmonary vessels distributed over the 
 walls of a sack or cavity, situated at the back of the 
 neck. The air admitted into this cavity oxygenizes the 
 blood. Those that inhabit the waters have to come 
 
LIMACIDJE. O 
 
 periodically to the surface for the purpose of respiration. 
 They have distinct heads, and are furnished with ten- 
 taculae and eyes. They move by the contraction of the 
 disks of their body. 
 
 The shells, when present, are mostly spiral or dis- 
 coid, sometimes patelliform. They are mostly external. 
 In the few instances in which they are internal, they 
 are imbedded in the mantle, and shaped like the finger 
 nail. They are hermaphrodite, and produce their 
 young by eggs, in which the embryos are observed par- 
 tially clothed with cilia, the movements of which are 
 obvious. 
 
 In this section we have six tribes. 
 
 TRIBE I. LIMACID^E. 
 
 Animal The well-known landslug. Body semi-cylindrical, soft 
 and fleshy, secreting abundant mucus through the pores 
 of the skin; the breathing cavity covered by a cloak or 
 disk, in the right margin of which the respiratory orifice, 
 and the vent are observable ; the head retractile with 
 four retractile tentacles, the upper two provided with 
 eyes ; mouth furnished with teeth, with single and long 
 projecting tops. 
 
 Shell Either wanting or embedded in the cloak or disk which 
 covers the front part of the body. They feed either at 
 twilight or during the night. It includes three genera 
 Arion, Geomalacus and Limax. 
 
 TRIBE II. TESTACELLID^:. 
 
 Animal With elongated body, semi-cylindrical, tapering in 
 front; disk covering and combined with the upper surface 
 of the body, bearing an external shell at the hinder part 
 of the back ; head with four tentaculce, the upper two 
 bearing the eyes, breathing orifice under the right side of 
 the shell, the vent near to it ; reproductive orifice behind 
 the upper tentacle on the right side. 
 
 Shell External, earshaped, compressed, with a very short 
 spire ; mouth very large with a thin outer lip slightly 
 notched at the hinder part. It contains one genus 
 Testacellus. 
 
GASTEROPODA. 
 
 TRIBE III. HELICIDJE. 
 
 Animal Head well developed, with four cylindrical retractile 
 tentaculee, the upper ones always prominent, bearing on 
 their summits the eyes ; end of the tail tapering, without 
 a gland; cavity of the lungs in the anterior part of the 
 body, at the under part of the edge of which is the breath- 
 ing hole ; at the outer base of the right tentacle is the 
 orifice of the generative organs. Motion produced by the 
 successive expansions and contractions of the muscular 
 foot. 
 
 Shell Spiral, often turreted, rarely depressed or expanded, 
 never operculated, but this deficiency is made up by the 
 animal, just before hibernating, closing the orifice with a 
 membraneous epiphragm, which will always be found per- 
 forated for the admission of air This is by far the 
 largest tribe, including eleven genera Vitrina, Zonites, 
 Helix, Buliraus, Pupa, Balsea, Clausilia, Zua, Azeca, 
 Achatina, Succinea. 
 
 TRIBE IV. LIMNVEAD^E. 
 
 Animal With a conical spiral body; an elongated foot; short 
 muzzle with dilated lips, and two compressed tentacles of 
 considerable size, with the eyes placed near their outsr 
 base. The tongue is armed with numerous toothed den- 
 ticles. No operculum. 
 
 Shell Variously shaped, spiral, turreted, dextral or sinistral, 
 discoid and even patelliform. Pale, uniform coloured, 
 and clothed with a hard olive or brownish periostraca. 
 It includes four genera Physa, Planorbis, Limnseus, and 
 Ancylus. 
 
 TRIBE V. AURICULID^E. 
 
 Animal With, a broad and ringed muzzle, on which are two 
 subtriangular and cylindrical tentaculce, with eyes near 
 the inner bases. They have numerous hoolced teeth, 
 similar to the Limnceadcs. Foot nearly ovate, without 
 operculum. 
 
 Shell Spiral ovate, with denticulated apertures. The septa 
 between the whorls of the shell at the extremity of the 
 body are imperfect. It includes two genera Conovulus 
 and Carychium. 
 
CYCLADID^E 7 
 
 TRIBE VI. CTCLOSTOMIDIJE. 
 
 Animal With a spiral body; two tentaculce with eyes at their 
 
 inner bases; foot ovate. Terrestrial. 
 Shell Ovate and turreted, strong; mouth oval ; operculum 
 
 consisting of several whorls. It includes, according to 
 
 the present arrangement, two genera Cyclostoma and 
 
 Acme. 
 
 CYCLADID^E. 
 
 CYCLAS. Brugiere. 
 
 Shell Subglobose, equivalved, more or less finely stri- 
 ated ; cardinal teeth small, sometimes undis- 
 tinguishable, one in the right and two in the left 
 valve. Lateral teeth developed transversely, dis- 
 tinguished from the Pisidia by being larger, 
 rounder, and more equilateral. 
 
 Animal Mantle produced behind forming a siphon, 
 which is divided into two nearly equal tubes. 
 
 C. RIVICOLA. Leach. PL I, fig. 2. 
 
 Shell subglobose, striated concentrically ; umbones obtuse; cardinal 
 ligaments distinct. 
 
 Tellina cornea ; var. B. Linn. Cyclas cornea, Drap. 
 
 This is the largest of British Cycladidae. Its form is 
 roundish, oval, and very slightly inequilateral. It is 
 comparatively strong and opaque. The valves are 
 covered more or less closely with concentric striae, 
 which are less distinct on the umbones. The epidermis 
 is glossy and of a brownish green, with darker zones ; 
 the umbones have generally a yellow tinge. Interior 
 of a bluish white colour. 
 
 Ordinary length five-sixths of an inch, and breadth 
 two-thirds of an inch. 
 
 The tubes of the animal slightly tinged with brown, 
 foot and mantle white. 
 
 Hob. The river Thames in considerable abundance; 
 it has also been found in the Trent, New River, Lea, 
 
8 CYCLADID.E. 
 
 Isis, Cherwell, Mersey, Foss, and other streams in 
 
 Yorkshire, &c. 
 
 C. CORNEA. Linnaus. PL I, fig. 3 and PL VIII, fig. 8. 
 
 Shell subglobose, slightly striated concentrically; umhones obtuse; 
 ligaments indistinct. 
 
 Tellina cornea, Linn, Penn. Cylas rivalis, Drap. 
 Tellina rivalis, Mull. Cardium corneum, Pult., fyc. 
 
 The shell of this widely-distributed Cyclas is rather 
 thin, and very finely striated. The valves are much 
 swollen in specimens that are fully formed , and of a 
 fawn colour ; younger ones a dirty yellow. Length 
 half an inch, and breadth five-twelfths. Tubes of the 
 animal slightly tinged with flesh colour, foot and 
 mantle white. 
 
 Hob. Abundant in almost every district, inhabiting 
 slowly-running streams and sometimes stagnant ponds. 
 
 C. CALICULATA. Draparnaud. PL I, fig. 4. 
 Shell rather rhombic, umbones prominent, capped. 
 
 Cyclas lacustris, Turt, Gray, fyc. Tellina lacustris, 
 Linn. Cardium lacustris, Mont. 
 
 The prominent umbones and extremely fragile char- 
 acter of this species, will readily distinguish it from its 
 congeners. The surface is glassy, of a greyish ash 
 colour, and the valves much more compressed than in 
 C. cornea. We have found specimens of this shell one 
 third of an inch long and five-twelfths broad, but they 
 are commonly rather smaller. 
 
 Hob. It is by no means an abundant species, but 
 seems to be more plentiful in the north than the south 
 of England. It inhabits stagnant pools and ditches. 
 
 C. LACUSTRIS. Draparnaud. PL I, fig. 5. 
 
 "Shell subrhombic, elongate, ovate, thin, inequilateral, and rather 
 compressed, especially below, where the valves meet each other at an 
 acute angle ; a little swollen behind the umbones." 
 
 A large individual measured five lines in length, and 
 seven in breadth. The general appearance of the 
 species is that of a greatly produced caliculata.. but de- 
 void of the characteristic beaks. 
 
pisimuM. 9 
 
 Hob. Specimens of this shell from which the above 
 description has been taken, are in the valuable collection 
 of Mr. Jeffreys, marked 'Exmouth, 1831, and Dr. Tur- 
 ton's Cabinet,' which seem to be the only specimens 
 ever found in Britain* 
 
 PISIDIUM. Pfeiffer. 
 Shell Suboval, equivalve, inequilateral, more or less 
 
 concentrically striated. Hinge and lateral teeth 
 
 similar to Cyclas. 
 Animal Mantle produced behind into a single undivided 
 
 tube. Foot tongue-shaped and very extensile. 
 
 P. OBTUSALE. Pfeiffer. PL I, fig. 6. 
 Shell globose, finely striated, with blunt projecting umbones. 
 
 This is the smallest of British Pisidia, seldom exceed- 
 ing one ninth of an inch in length. The depth is equal 
 to the breadth, both being somewhat less than the 
 length. It may be distinguished by its swollen valves, 
 which give it a roundish oval shape. Umbones nearly 
 central. It is generally covered with a rough epider- 
 mis of a greenish black colour, margined by a yellowish 
 zone, which, when removed, presents a glossy pale yel- 
 low surface. 
 
 Hab. It occurs not unfrequently in Cambridgeshire 
 and Oxfordshire, inhabiting small splash pools, and 
 other stagnant waters, and though not common in Scot- 
 land or Ireland, several localities in both countries have 
 been recorded. 
 
 P. PUSILLUM. Turton. PI. I, fig, 7. 
 
 Shell orbicular, oval, scarcely inequilateral, slightly striated; um- 
 bones broad and but slightly prominent 
 
 Cyclas fontinalis, Drap, fyc. Cyclas pulsilla, Turt. 
 
 This species approaches nearest in form to P. obtusale, 
 the umbones being nearly central; but it is more com- 
 pressed and less glossy, when the epidermis, common 
 to most of the species, has been removed. Its colour is 
 generally a tawny white. It sometimes attains a seventh 
 of an inch in length and an eighth in breadth. 
 
 * Forbes andHanley's " British Mollusca," Vol. II, pp. 118, 119. 
 
10 CYCLADTD^E. 
 
 Hal. It is very generally distributed, inhabiting 
 stagnant pools, frequently in great abundance. 
 
 P. CINEREUM. Alder. PL I, fig, 8. 
 
 Shell broadly ovate, greyish, rather compressed, finely striated with 
 one or two evident sulcations which form darker zones across the 
 shell; umbones obtuse, and slightly produced. 
 
 The peculiar milky ash colour and dark zones, to- 
 gether with the compressed shape of this shell, readily 
 distinguish it from the other Pisidia, independently 
 of its being much larger (P. amnicum excepted.) We have 
 found specimens about a quarter of an inch long, and 
 one fifth broad, in a running stream in the neighbour- 
 hood of Guisbro' in Cleveland, though it is generally 
 rather less. 
 
 Hab. It is by no means so common as some of the 
 other species. Stagnant or still pools it most frequently 
 inhabits, though sometimes found in running streams 
 and even rivers. Scabro', near Newcastle, Preston, 
 Croydon Canal, Bath, and Exmouth are recorded locali- 
 ties. It is distributed sparingly over Ireland and Scot- 
 land. 
 
 P. NITIDUM. Jenyns. PI. I, fig. 9. 
 
 Shell orbiculate, very shining, oval, with fine striae, more deeply 
 marked on the umbones. 
 
 The animal, according to Jenyns, is white ; siphon 
 short and funnel shaped, with a patulous aperture, the 
 margin of which is more or less crenated or plicated. 
 The shell of this species is difficult to distinguish from 
 P. pusillum, except by the deeper striae upon the um- 
 bones (which require a searching examination), and its 
 lustrous appearance, being seldom coated with mud. 
 The larger specimens are an eighth of an inch in 
 length, and nearly as broad. Jenyns first described 
 this shell in the Trans, of Cambridge Phil. Soc., from 
 specimens obtained in the ditches in Battersea Fields 
 and other parts of Surrey, where, he says "it is widely 
 distributed but seldom abundant." 
 
 Hab. Streams of clear water, Surrey. It has also 
 been found near Scarbro', in Northumberland, near 
 
P1SID1UM. 11 
 
 Darlington, and North Stainley, near Bipon, &c. It is 
 generally distributed in Ireland, and several localities 
 are recorded in Scotland. 
 
 P. PULCHELLUM. Jcnyns. PL I, fig. 10. 
 
 Shell obliquely ovate, deeply striate, inequilateral; umbones simple, 
 rather blunt. 
 
 Pisidium fontinale, Brown. Cyclas fontinalis, Brown. 
 
 This species varies very much both in shape and 
 size, sometimes being smaller than P. obtusale, and 
 sometimes almost, as large as P. cinereum ; but it may 
 generally be known by its deeper striae, more shining 
 appearance, and by being more inequilateral than the 
 others which have been described. On account of the 
 multiplicity of shapes which this shell assumes, many 
 varieties have been appended to the species, by most 
 conchologists, all of which seem more or less to diverge 
 into one another. Its colour varies from an ashy hue 
 to a yellowish white. 
 
 Hob. It is one of the commonest of the smaller 
 Pisidia, being distributed generally over England, 
 Ireland, and Scotland ; inhabiting both running streams 
 and stagnant pools. 
 
 P. HENSLOWIANUM. Sheppard. PI. I, fig. 11. 
 
 Obliquely oval, finely striated, ventricose ; umbones acute, with a 
 laminar projection. 
 
 With the exception of the laminar projection and its 
 greater ventricoseness, the description of P. pulchellum 
 would equally apply to this species. The surface is 
 generally rather glossy, of an ashy grey or yellowish 
 horn colour. The length varies from a sixth of an 
 inch to two lines and a half. 
 
 Hob. Ditches and slowly flowing streams ; the re- 
 corded localities are few. River Cam, Thames at Hen- 
 ley, Ackworth, and several places near Oxford.* 
 
 * James Dalton, B.A., who has kindly furnished us with many 
 localities, states " it has become abundant since the introduction of 
 the American ANACHARIS ALSINASTRUM. Formerly the shell was very 
 rare." 
 
12 UNIONID^E. 
 
 P. AMNICUM. Mutter. PI. I, fig. 12. 
 
 Ovate; very inequilateral, deeply suleated, striated; umbones, 
 somewhat blunt. 
 
 Tellina amnica, Mull, Turt, Sfc. Cylas amnicum, 
 Turt. 
 
 This species is more inequilateral than any other 
 Pisidium, and considerably larger in size. These cha- 
 racteristics, together with the deep sulcations and strise, 
 will readily distinguish it from its congeners. The 
 valves are moderately ventricose in adult, though much 
 compressed in young specimens. It is comparatively 
 strong ; and though generally semi-transparent, it is 
 frequently scarcely diaphanous. Of an olivaceous ash 
 colour, with a broad marginal zone of a yellow tint. 
 
 Specimens may sometimes be found nearly half an 
 inch in length, and a third in breadth. 
 
 Hob. An abundant species; delighting more es- 
 pecially in running streams, though by no means con- 
 fined to them. 
 
 UNIONISE. 
 UNIO. Retzius. 
 
 Shell Equivalve, inequilateral; hinge, with two teeth 
 in each valve, the one short, irregular, and sub- 
 striated, the other elongated, compressed, lateral; 
 ligament exterior. 
 
 Animal Thick, mantle freely open in front, with simple 
 edges; branchial region fringed with numerous 
 cirrhi. Foot large, broad, compressed. 
 U. TUMIDUS. Retzius. PI. Ill, fig. 2. 
 
 Wedge shaped; tumid ; umbones prominent ; rugose; anterior teeth 
 thick, high, and conical. 
 
 Unio Ovalis. Flem, fyc. 
 
 The external appearance, both as regards colour and 
 shape, varies considerably in this shell, still it is not 
 very difficult to distinguish it from the only other re- 
 cognized British species. It is extremely solid, with large 
 and strong anterior teeth. The valves are unequally 
 ventricose, swelling in front, and compressed behind ; 
 
UNIO. 13 
 
 the surface being generally painted more or less dis- 
 tinctly with rays of colour, varying from brown to a 
 bright green or yellow; occasionally they are met with 
 of a uniform brown, or purplish tinge. They vary 
 from two and a half to three inches in length, by about 
 an inch and a half in the broadest part. 
 
 Hob. Found abundantly in some of the streams in 
 the south of Lancashire and Yorkshire; it has also been 
 found in the New River, Avon, Kennet, Ouse, &c. 
 
 U. PICTORUM. Linnceus. PI. Ill, fig. 1. 
 
 Oval, oblong, posterior end not cuneiform ; of a yellowish green colour 
 interspersed with brownish zones; anterior teeth, compressed, elevated, 
 crenate. 
 
 Mya pictorum. Linn. Unio rostrata. Lam. 
 
 One of the distinguishing peculiarities of this Unio is 
 that its dorsal and ventral margins run almost parallel. 
 The rays of colour also generally so conspicuous in U. 
 tumidus are wanting here. Internally it is white, or 
 approaching salmon colour. It frequently attains a 
 greater length than U. tumidus ; breadth about the 
 same. 
 
 Hob. The recorded localities are numerous, Ken- 
 net, Avon, several of the Yorkshire rivers, Severn, and 
 almost all canals having a muddy bottom ; it has not 
 been found further north than "Winyard. 
 
 U. Batavus, and U. ovalis we have rejected, the 
 former appears to be foreign, and the latter only a dis- 
 torted form of U. tumidus. 
 
 U. MARGARITIFEK.US. LiuHCBUS. PL I, fig. 1. 
 
 Ovate, oblong, thick, solid; epidermis brownish black; cardinal 
 teeth, thick, conical; no lateral teeth. 
 
 Mya margaritifera, Linn, Retz., fyc. Alasmodon 
 magaritifera, Gray. 
 
 This is the shell which obtained so much celebrity 
 amongst the ancients on account of the pearls which are 
 sometimes found in the body of the animal. These 
 pearls seem to be malformations, and are generally 
 formed between the two films or skins that line the 
 
14 ANADONTA. 
 
 shell. Their composition is much the same as that of 
 the inner portion of the shell, being nacreous, and pos- 
 sessing a dull lustre. Some naturalists suppose they 
 are caused by particles of sand, or other irritating sub- 
 stances, getting into the stomach, or other organs; and, 
 the animal to remedy the annoyance, surrounds them 
 with a coating of pearl. Others affirm that they are 
 the products of disease, and correspond to the calculi 
 in some animals. 
 
 The average length is from four to five inches, and 
 about two in breadth. 
 
 Hob. Most frequently found in mountain streams, 
 hence they are abundant in Wales, Cumberland, Lan- 
 cashire, the north of Yorkshire, and the hilly parts of 
 Cornwall and Devon. The Linn, Eden, and Yorkshire 
 Esk abound with them. 
 
 ANADONTA. Brugiere. 
 
 Shell Ollong, equivalve, generally thin in proportion to the 
 size ; inequilateral ; hinge without teeth, but furnished 
 with a lamina. 
 Animal Much the same as Unio. 
 
 A. CYGNEA. Linnceus. PI. II, fig. 1. 
 
 Perhaps no shell illustrates the change of form and 
 appearance, which the same species exhibits, from being 
 matured under different circumstances as regards climate, 
 geological formation, and the nature of its food, more evi- 
 dently than the present. By some writers it has been 
 divided into a number of species, whilst others have en- 
 deavoured to classify the different forms under several 
 varieties. The former arrangement is, however, quite 
 exploded, while in adopting the latter, we own it offers 
 many difficulties. 
 
 The normal form is elongated oval, moderately ven- 
 tricose, not very solid ; the lines of formation at pretty 
 regular distances ; posterior end, not beaked, but round- 
 ly attenuated. 
 
 The colour of the epidermis is olivaceous yellow 
 green. 
 
ANADONTA. 15 
 
 var. CELLENSIS. Gray. Shell larger, more ventri- 
 cose, thinner, and more brittle ; more produced behind, 
 and epidermis of a greener tint. 
 
 Hal). Ponds in very still water. 
 
 var. VENTRICOSA. Pfeif. Valves more solid and 
 swollen ; in shape, rhombic oval ; the epidermis being 
 often beautifully coloured. 
 
 var. ANATINA. Pfeif. Smaller than the above ; 
 some of the lines of growth so indistinct as to show a 
 considerable breadth smooth and glossy ; hinder ex- 
 tremity broad and sub-rhomboidal ; dorsal line rising 
 behind so as to give it a winged appearance ; epidermis 
 a bright green with rayed lines. 
 
 var. ROSTRATA. Pfeif. Rather rhombic ; much 
 produced behind, so as to form a sort of beak ; short 
 and rounded in front ; colour generally brownish. 
 
 var. AVONENSIS. Gray. Very nearly connected 
 with the preceding, but more rounded; ventricose, 
 thick, solid, and slopes rather angularly behind. 
 
 Hob. The localities of this species are so numerous 
 that it is less difficult to say where it is not, than where 
 it is found. Though lakes and ponds which have a 
 constant influx of fresh water, but possess, at the same 
 time, an unruffled surface, except when disturbed by 
 winds, seem most favourable to its perfect development, 
 yet running streams with sandy or gravelly bottoms 
 furnish a stunted race of less pleasing appearance. In 
 collecting this species (as in others which vary much), 
 the young conchologist should carefully label his speci- 
 mens with the locality, adding a few remarks on the 
 nature of the water, the character of the bottom, or any 
 other circumstance which could have any effect upon 
 the shell, or its inmate. 
 
 MYTILID^E. 
 
 DREISSENA. Van Beneden. 
 
 Shell JEquivalve, very inequilateral, triangular ; character- 
 ized by a small transverse plate under the hinge within. 
 
16 NERITID^. 
 
 Animal Mantle closed, except a passage for the foot and two 
 syphons ; retracting muscular cords united into a single 
 bundle with one point of attachment. 
 
 D. POLYMORPHA. Pallas. PL III, fig. 3 and 4. 
 
 The remarkable rapidity with which this shell has 
 spread in numerous localities on our island, is one of 
 the most interesting facts connected with it, showing 
 how readily species become naturalized when the 
 climate and situation are suitable. Naturalists are un- 
 decided how it has got introduced, whether adhering 
 to the bottom of ships it has survived a passage through 
 the salt water of the sea from the mouths of rivers in 
 Sweden, Russia, &c.; or by adhering to the timber ex- 
 ported from those countries, it has remained alive for so 
 long a time out of water. 
 
 Hob. Most of our canals which communicate with 
 seaport towns in the midland and northern counties, 
 living in gregarious masses on stones and pieces of 
 timber. 
 
 NERITIDJS. 
 
 NERETINA. Lamark. 
 
 Shell Semiglobular; without an umbilicus ; generally thiclc ; 
 spire of few whorls, last whorl large; aperture semi- 
 circular, furnished with an operculum having a tooth on 
 its lower margin. 
 
 Animal Tentacles awl shaped ; eyes on short pedicels at the 
 outer side of their base ; foot rather short, triangularly 
 oblong. 
 
 N. FLITVIATILIS. 'Linnaeus. PL IV, fig. 1 and PL 
 VIII, fig. 1. 
 
 The peculiar markings of this shell, together with its 
 form, will readily distinguish it from any other of our 
 species. The dark ground is variously chequered with 
 spots of yellowish white, brown, purple, or pink, but 
 they are often obscured by an incrustation from the 
 water, which seems to serve as a protection from animals 
 which would otherwise seize them as prey. 
 
PALUDINA. IT 
 
 About three-eighths of an inch long, and a quarter 
 of an inch broad. Convex or flat above, and slightly 
 incurved underneath. 
 
 Hob. Rivers, especially the larger ones, as the 
 Thames, Trent, Ouse (near York), Humber, Severn, 
 and Avon. We have frequently obtained dead speci- 
 mens from the ballast hills near Middlesbro', which 
 have been brought from the mouths of other rivers. 
 
 PALUDINID.E. 
 PALUDINA. Lamark. 
 
 Shell Spiral, convex ; mouth nearly round, operculum long, 
 
 consisting of concentric rings, terminating in a small 
 
 nucleus on. the inner side ; epidermis coloured. 
 
 Animal With a lengthened muzzle ; foot large ; tentaculce 
 
 two, those of the male unequal. Female ovo-viviparous. 
 
 P. LISTERI. Forbes and Hanley. PI. IV, fig. 5, 
 and PL VIII, fig. 3. 
 
 Shell thin, spiral; five volutions very distinctly marked; mouth 
 large and open. 
 
 Paludina vivipara. Gray. 
 
 This shell is chiefly found in the midland and south- 
 ern counties. It may be distinguished from P. vivipara 
 by the volutions being more inflated, the shell thinner, 
 the last whorl larger and more open, and the whorls at 
 the apex very distinct, and terminating in a sharp point. 
 
 Full grown individuals measure about an inch in 
 length, by three fourths of an inch in breadth. 
 
 Hob. Slowly-running rivers and canals. The re- 
 corded localities are the rivers Ex, Taw, Lea, Isis (at 
 Blenheim), and a stream near York, &c. 
 
 P: VIVIPARA. Linnceus. PI. IV, fig. 6. 
 
 Sharper, and more produced than the last. Shell rather thicker and 
 not so translucid; volutions six in number, with brown bands running 
 parallel with the sutures. The colouring paler, the whorls less 
 prominent, and consequently the sutures not so deep ; mouth more 
 contracted ; apex blunt. 
 
 Paludina achatina. Gray, Lam, fyc. 
 
 Length the same as P. Listeri, but not quite so broad. 
 
 Hob. Abundant in the Cherwell, Oxfordshire, &c. 
 
18 PALUDINIDJE. 
 
 BITHINIA. Gray. 
 
 Shell More or less spiral, covered with a horny epidermis, of 
 a yelloiv colour ; mouth ovate, slightly angular above. 
 
 Animal Muzzle lengthened ; two tentacul(B with eyes at the 
 extremities, those of the male equal Foot obtuse, with 
 thick shelly operculum. Oviparous. 
 
 B. TENTACULATA. Gray. PL IV, fig. 7. 
 
 Oval, spiral, with five modertely convex volutions of a yellowish 
 colour, smooth and semitransparent ; no umbilicus. 
 
 Helix tentaculata, Linn. Paludina impura, Lam., 
 Sowb., fyc. 
 
 Medium size, about five-twefths of an inch in length, 
 and one in breadth, though we have met with indi- 
 vidual specimens much larger. It is seldom covered 
 with an extraneous epidermis, if covered, it is readily 
 removed, and presents a smooth, shining exterior. The 
 shell is moderately thick. Operculum thick and shelly. 
 
 Hob. Common all over England except the extreme 
 north. It is found in ditches, canals, and slowly-run- 
 ning streams. 
 
 B. LEACHII. Sheppard. PL IV, fig. 8. 
 
 Somewhat resembles the young of B. TENTACULATA, but is more coni- 
 cal, the whorls are better denned, and it has a small oblique umbilicus. 
 
 Bithinia ventricosa, Gray. Paludina ventricosa, 
 Brown. 
 
 Besides the above distinguishing characteristics, the 
 final volution is shorter, more ventricose and nearly 
 circular. Ordinary length a quarter of an inch, and 
 breadth two lines. 
 
 Hob. Many localities in the region of the Thames, 
 and the south of England generally ; but also met with 
 occasionally in the north. Streams near York and the 
 south of Durham. It is not so plentiful as the preced- 
 ing species. 
 
 VALVATA. Mutter. 
 
 Shell With a somewhat elevated or a discoid spire ; mouth 
 circular ; operculum horny, concentrically spiral. 
 
VALVATA. 19 
 
 Animal Muzzle produced ; cylindrical elongated tentacles, 
 with eyes at the hinder extremities. 
 
 V. PISCINALIS. Mutter. PL IV, fig. 4. 
 
 Somewhat globular, with an elevated deeply sutured spire of three 
 whorls, above the last volution ; umbilicus a whitish colour. 
 
 The two species of Valvata differ much in general 
 appearance, the one being comparatively long and spi- 
 ral, the other discoid and depressed. 
 
 Shell nearly a quarter of an inch in length and the 
 same in breadth. 
 
 Hob. Canals, streams, and ponds. It is generally 
 distributed all over the British Isles, though by no 
 means common in some districts. 
 
 V. CRISTATA. Mutter. PL IV, fig. 3. 
 
 Discoid, flat ; spire level or somewhat below the last volution. 
 
 The whorls are cylindrical, three in number and 
 deeply saturated. The shell is thin and of a light 
 horn colour ; about one tenth of an inch in diameter ; 
 somewhat resembles a PlanorUs, but is readily distin- 
 guished by the operculum. 
 
 Hob. Ditches and ponds in many parts of Britain, 
 and where found they are usually plentiful. Distri- 
 buted all over Ireland. 
 
 LITTORINIDJE. 
 
 ASSIMINIA. Gray. 
 Shell Spiral, conical, smooth. Operculum corneous. 
 
 Animal Head, muzzle-shaped; two tentacles with eyes at 
 the extremities. 
 
 A. GRAYANA. Jeffreys. PI. IV, fig. 2, and PL 
 VIII, fig. 2. 
 
 Ovate ; of a brown colour ; mouth of the animal elliptical. 
 
 This shell is never found except in brackish water. 
 The spire which consists of several whorls is rather 
 acute. It is about a quarter of an inch in length. 
 
 Hab. The mouths of rivers amongst confervce, &c. 
 c 2 
 
U LIMACID.E. 
 
 Found plentifully at Greenwich marshes and other 
 places in the south of England. 
 
 LiMAcnm 
 
 ARION. Ferussac. 
 
 Shell Oblong, generally of a soft spungy nature, but hardens 
 upon exposure to the atmosphere, situated in the disk 
 covering the anterior part of the body, undeveloped. 
 
 Animal Somewhat cylindrical, lanceolate ; tentacles four in 
 number, two of which have eyes at their extremities ; 
 mantle elliptical. 
 
 A. EMPIRICORUM. Ferussac. PL V, fig. 1. 
 
 Body generally black, and somewhat grooved ; shield ovate ; shell 
 spongy. 
 
 Limax ater, Linn. Arion ater, Gray. 
 
 So abundant, that during wet weather the fields and 
 paths are strewed with them in all directions. They 
 are naturally herbivorous, though at times carnivorous, 
 and so voracious that they do a great amount of injury 
 to the farmer and gardener, who wage an exterminating 
 war with them and others of the mollusca family. It is 
 somewhat variable in colour according to the locality 
 and other natural circumstances ; the prevailing hue is 
 a slaty black, but it is occasionally of a reddish brown, 
 and sometimes almost white.* 
 
 Hob. Woods, gardens, and moist places all over 
 Britain. 
 
 A. FLAVUS. Mutter. PI. V, fig. 4. 
 
 More elongated than A., empiricorum ; disk more oblong ; secreting 
 a yellow mucus. 
 
 About an inch in length and of a whitish colour, ex- 
 cepting the shield and posterior parts, which are a faint 
 yellow. 
 
 * The best way of preserving the land slugs for collections is in 
 spirits of wine. They can be deprived of life almost instantaneously 
 by pouring boiling water over them, which should be done while the 
 animal is stretched out. They should be then placed in a small glass 
 tube, one end of which has been closed, the tube filled with spirits of 
 wine and the other end closed. 
 
GEOMALACUS. 
 
 Hab. Moist and rocky places. The only recorded 
 locality is at the side of the turnpike road, Westgatc 
 Hill. 
 
 A. HORTENSIS. Ferussac. PL V, fig. 3. 
 
 Slaty blue colour, streaked, elongated, shell rather concave. 
 
 This pretty little slug is common in the north of 
 England, both in woods and gardens, in company with 
 A. empiricorum. It is variable both in size and colour, 
 but seldom measures more than an inch and a half in 
 length, and is always streaked along the upper part of 
 the body. 
 
 Hab. Moist woods and gardens, where it should 
 be sought for immediately after a shower, in summer 
 weather. 
 
 GEOMALACUS. Allman. 
 Shell Ovate, in a sheath similar to Arion. 
 Animal Elongated cylindrical, lanceolate ; four tentacles, 
 two of which are furnished with eyes. 
 
 G. MA\CULOSUS. Allman. PL V, fig. 6. 
 
 This genus is distinguished by the position of the 
 respiratory orifice, being at the right side of the disk at 
 the anterior margin, the caudal gland, and the position 
 of the reproductive orifice. It is by far the most beau- 
 tiful of the slug tribe, the body being spotted with 
 bright yellow. 
 
 Hab. The south of Ireland, in damp rocky situations. 
 In many places plentiful. 
 
 LIMAX. Linnczus. 
 Shell Oval, of a white or cream colour, and found embedded 
 
 in an oblong disk. 
 
 Animal Head furnished with four tentacles, two of which 
 have eyes, retractile like the former; tail lanceolate with- 
 out a mucous gland ; spiracle on the hinder margin ; 
 pulmonary cavity behind it ; orifice of the reproductive 
 system at the hinder side of the right tentacle. 
 
 L. AGRESTIS. Midler. PL IV, fig. 9. 
 
 Of a grey colour, mantle large, ovate and rounded behind ; shell 
 small ; keel short and always slanting. 
 
22 LIMACIDyE. 
 
 The commonest, the most voracious, and consequently 
 the most destructive to almost all kinds of vegetables is 
 this little slug ; it is the pest of the flower garden, 
 which seems to be its favourite resort. It is said to pro- 
 duce many families in a year, and has been known to 
 lay as many as two hundred eggs at one time ! The 
 mucus is white, which when dry leaves a white streak. 
 
 Hob. Almost every garden in the country ; also 
 fields, damp lanes, &c. 
 
 L. CINERETJS. Muller. PI. IV, fig. 12. 
 
 Animal of a cinereous colour, with elongated spots on the hack 
 keel long and straight, somewhat carinated ' towards the extremity ; 
 shield produced behind ; shell thin, flat, slightly concave, and pearly 
 white. 
 
 Limax maximus, Gray. 
 
 The largest of the Limaces, sometimes measuring five 
 or six inches in length. It is not so common as the for- 
 mer species, though found plentifully in all parts of the 
 British Isles. The shell is large, generally measuring 
 five or six lines in length and somewhat more than half 
 the breadth. The animal when at rest does not contract 
 its body, like most of the other land slugs, into a semi- 
 spheroid, but simply withdraws its head under the 
 mantle. 
 
 Hab. Common everywhere in suitable places. It 
 prefers a shady situation under trees and stones. 
 
 L. ARBORTJM. Bouchard Chanter eux. PL IV, fig. 14. 
 
 Back round, somewhat flatter at the tail ; shield peculiarly wrinkled* 
 obtuse in front but pointed behind, of a peculiar tawny grey colour ; 
 shell of an oblong shape, rather convex above and concave below. 
 
 This snail is usually found under decayed wood, on 
 which it is said to subsist, and hence obtains the name 
 of the tree slug. It resembles cinereus in some of its 
 stages, but seldom attains the same size, and may be 
 distinguished from it by the position of the spiracle and 
 the shape of the mantle ; it is also more attenuated, the 
 hinder part more lanceolate, and the anterior tentacles 
 much shorter. 
 
LIMAX. 
 
 Hal. Generally distributed over the British Isles, 
 on trees or near them. 
 
 L. FLAVUS. Linnceus. PI. V, fig. 4. 
 
 Yellowish brown colour, head and tentacles bluish ; mantle large, 
 rounded behind, wrinkled ; the extremity of the tail carinated ; shell 
 thin. 
 
 Limax variegatus, Drap., 8fc. 
 
 The cellar slug is a large species about the same size 
 as L. cinereus, but differs from it in having a smaller 
 head, smaller tentacles, and being generally of a yellow- 
 ish grey or fawn colour. The mucus is colourless. The 
 shell is oval, extremely thin, four or five lines in length, 
 and of a pearly white colour. 
 
 Hob. Plentiful in almost every damp cellar, and 
 other dark, damp places. The recorded localities are 
 few, but there is no doubt of its being abundant all 
 over England. 
 
 L. BRIINNEUS. Draparnaud. PL V, fig. 2. 
 
 Uniform dark brown colour; with a paler mantle, which is wrinkled; 
 neck long ; the extremity of the tail carinated. 
 
 This slug is similar in size and shape to agrestis, 
 being about an inch in length. The mucus is colourless. 
 
 Hob. The only recorded localities for this slug are 
 in the north-east of England ; we have found many spe- 
 cimens in various parts of Cleveland, Yorkshire, though 
 it is by no means plentiful. It is found in similar situa- 
 tions to the other Limaces, taking refuge under stones 
 during the dry weather. It is probably partial to a 
 damp peaty soil. 
 
 L. TENELLUS. Muller. PL IV, fig. 14. 
 
 Back rounded, compressed near the tail ; shield wrinkled ; colour 
 yellow ; mucus yellow. 
 
 The rarest of British slugs. Only one specimen has 
 been met with, which was discovered in a wood at 
 Allansford, near Shotley Bridge. It does not exceed 
 an inch and a quarter in length. Tentacles black. The 
 shield is rounded behind and covered with fine concen- 
 tric circles. 
 
TESTACELLID^E. 
 
 L. SOWERBII. Ferussac. PL IV, fig. 10. 
 
 Mantle short, truncated behind ; granulated ; yellowish brown 
 colour; tentacles bluish black; shell small, oval, and convex beneath; 
 keel obvious. 
 
 L. carinatus, Gray. 
 
 This slug may be distinguished by its prominent keel 
 and short truncated mantle. It is about three inches in 
 length. The shell is two or three lines long. 
 
 Hob. Gardens and damp places in the south of Eng- 
 land. We have found single specimens in the north of 
 Yorkshire, though by no means common. Many locali- 
 ties in Ireland are recorded. 
 
 L. GAGATES. Draparnaud. PL IV, fig. 11. 
 Obtuse, back carinated, bluish grey colour, lanceolate. 
 
 This rare slug is only recorded as having been found 
 in one place in England, but has been taken in many 
 places in Ireland. The mantle is very obtuse, and in 
 outward appearance much more resembles that of an 
 Arion than a Limax. The shell is small, oval, and 
 plano-convex. The head is of the same colour as the 
 body, but the tentacles are generally rather darker. 
 
 Hob. Shady places under stones, Ireland. 
 
 TESTACELLID^E. 
 TESTACELLA. Cuvier. 
 
 Shell Strong and large for the size of the animal, situated at 
 
 the extremity of the body ; external, auriform-shape, with 
 
 a minute spire. 
 Animal Elongated; of a yellowish, reddish, or grey hue; 
 
 tentacles cylindrical, four in number, the two anterior 
 
 ones being furnished with eyes. 
 
 T. HALIOTOIDEA. Draparnaud. PL V, fig. 5. 
 
 Testacellus haliotoideus, Gray, fyc. 
 
 This species is confined to the south of England, and 
 Ireland, where it has been most probably introduced ; 
 it was first found in the Channel Isles. The genus is 
 intermediate between the slug and the snail ; the shell 
 
VITRINA. 25 
 
 and animal being like the former, but differing from it 
 in the position of the shell, which is placed on the 
 posterior part of the body and external. They are car- 
 nivorous, and live for the most part in holes under the 
 ground. 
 
 Hob. The islands of Guernsey and the other Chan- 
 nel islands, and in or near nursery gardens in the south 
 and south-west of England. 
 
 A spurious species, T. Maugii, has been introduced 
 by some conchologists, from having been found in a 
 nursery garden near Bristol, and at Devizes. 
 
 HELICIDJE. 
 
 VITRINA. Draparnaud. 
 
 Shell Exceedingly thin, subglobular, with a depressed spire 
 
 of a few whorls ; pellucid. 
 Animal Lanceolate ; mantle large, furnished with a lobe on 
 
 the right side. 
 
 V. PELLUCIDA. Mutter. PI. V, fig. 12. 
 
 Shell small in proportion to the animal, very thin, diaphanous, 
 colour varying from a white or yellow tint, to that of a beautiful green 
 
 Helix pellucida, Mull. H. elliptica, Brown. 
 
 This beautiful little mollusk is a connecting link be- 
 tween the slugs and snails, having the shield-like mantle 
 of the one and the external globular shell of the other. 
 The animal also is only partly retractile. The shell is so 
 thin and brittle that a very slight crush would break it. 
 It is as its name implies vitreous, more so perhaps than 
 any other shell. 
 
 Hob. Plentiful in all parts of the country among 
 moss, or buried a few inches under the surface of the 
 ground. May be found among decayed leaves and 
 peat, when not too moist, in great abundance. 
 
 ZONITES. Gray. 
 Shell Spiral, more or less discoid ; spire of many whorls, 
 
 depressed ; mouth nearly circular. 
 Animal Lanceolate, tentacles four, the posterior ones small ; 
 
 mantle reflexed. 
 
26 HELICID^E. 
 
 Z. CELLARIUS. Muller. PL V, fig. 8. 
 
 Shell discoid, opaque white beneath, a yellowish horn colour above, 
 shining and smooth ; whorls five or five and a half in number. 
 
 Helix cellaria, Mull., fyc. 
 
 There is sometimes a difficulty in distinguishing this 
 species from Z. alliarius, when the animal is not pres- 
 ent, but there is in the one under notice a peculiarly 
 pellucid milkiness of colouring, which is never present 
 in the succeeding species ; the spire also is more flat- 
 tened, and it attains to a considerably larger size ; in 
 fact it is the largest of our Zonites, sometimes measuring 
 half an inch in diameter, when found in favourable situ- 
 ations as drains and sewers. They prefer damp places 
 amongst luxuriantly growing weeds. We were once 
 somewhat surprised, when turning over a plot of ground 
 in the early part of the spring, to find a number of these 
 shells, frequently at the depth of eight or ten inches 
 below the surface, where no doubt they had descended 
 to pass the winter in a state of torpor, and the weather 
 had not been sufficiently genial to call them forth into 
 more active life. 
 
 Hob. May be found in almost every district very 
 abundantly, at the roots of damp grass, moss, &c. 
 
 Z. ALLIARIUS. Miller. PL V, fig. 13. 
 
 Shell slightly convex, nearly flat, thin, horn coloured, smooth and 
 shining ; four volutions ; slightly white underneath and near the um- 
 bilicus. 
 
 Helix alliaria, Brown, fyc. 
 
 Though the family of Zonites is somewhat puzzling 
 to beginners, yet we think, by a little close attention, 
 the diligent observer will be able to overcome the diffi- 
 culties which he may meet with ; perhaps the greatest 
 obstruction is the liability to confound the young of the 
 larger, with the full grown smaller ones. Z. alliarius 
 when living may always be easily distinguished from 
 the rest, by the strong garlic smell which the animal 
 emits, especially when irritated; this is a remarkable 
 fact and has no parallel amongst the other British Land 
 
ZONITES. 27 
 
 and Fresh-water Molluscs ; for what purpose it is de- 
 signed we are quite ignorant, though probably as a 
 means of defence. It approaches nearest to Z. cella- 
 rius and nitidulus in general appearance and form, but 
 from the former it may be known by its small size and 
 darker colour, besides not being so flat in the spire ; 
 whilst it is darker than the latter and more lustrous. 
 
 Hdb. It is universally diffused through the British 
 Isles, in various localities ; its most favourite haunts are 
 woods, amongst the grass and moss at the roots of trees, 
 under stones, and logs of fallen timber. 
 
 Z. NITIDTJLUS. Draparnaud. PL V. fig. 9. 
 
 Shell flat, of a dull waxy appearance above, dirty yellowish horn 
 colour, opaque ; mouth large. 
 
 Helix nitidula, Alder., fyc. 
 
 This is almost sure to be the first Zonites with which 
 the young naturalist will form an acquaintance, for there 
 is not a hedge-row, wood, or garden where it may not 
 be met with ; almost every locality seems favourable, 
 though like most of the Zonites it prefers the damp 
 wood. The only species with which it is likely to be 
 confounded are cellarius and alliarius, from both it 
 may be distinguished by the absence of that lustre 
 which is a marked feature in their appearance. 
 
 The shell is about three tenths of an inch in diameter. 
 
 Hob. Exceedingly plentiful, almost every hedge- 
 row will furnish a number of specimens at the roots of 
 grass. 
 
 Z. PURUS. Alder. PI. V, fig. 14. 
 
 Shell depressed, smooth, transparent white ; whorls four ; umbilicus 
 large. 
 
 Helix nitidula, Drap. Helix pura, Brown, Alder. 
 
 This is the most delicate of the Zonites, being fragile 
 and generally of a transparent white colour, though 
 there is a variety of a light horn colour, about one 
 eighth of an inch in diameter. The species with which 
 this may be confounded are radiatulus and crystal- 
 linus. It is destitute of the longitudinal markings so 
 
28 HELICID^E. 
 
 apparent and universal in radiatulus, whence its name ; 
 radiatulus is also a stronger shell, and the outer whorl 
 greater in comparison to the size. Crystallinus is 
 much smaller and always of a milky white colour 
 throughout, and remarkably thin. 
 
 Hdb. Hedge-rows and woods are its favourite re- 
 sorts, generally preferring a moist situation, adhering 
 to the decaying leaves, and lurking amongst the roots 
 of grass and moss. 
 
 Z. RADIATULUS. Alder. PI. V, fig. 10. 
 
 Shell depressed, horn colour, regularly striated on both disks; 
 whorls four; umbilicus large. 
 
 Helix radiatula, Brown, Sfc. 
 
 This is one of the most interesting species of the 
 genus, partaking as it does somewhat of the character 
 of a Helix, and seems to be the connecting link between 
 the two. This is more strikingly the case if we pay 
 much regard to the old distinction of a streaked outer 
 lip being" characteristic of a Helix in contradistinction 
 to a Zonites. If a full grown specimen of this shell be 
 carefully examined, the streakings of the outer lip can- 
 not fail to be perceived, the lip is also of a different 
 colour, being whitish, and is more opaque than the rest 
 of the shell. 
 
 The longitudinal ridges and furrows, together with 
 the greater depth and breadth of the outer whorl in 
 comparison with the rest of the shell, will readily dis- 
 tinguish it from the brown variety of Z. purus, for 
 which alone it can be mistaken. About one fifth of an 
 inch in diameter. 
 
 Hob. We have met with it most abundantly in old 
 grassy fields or commons, where the ground is some- 
 what damp and favours the growth of mosses, at the 
 roots of which it is generally found. 
 
 Z. NITIDUS. Midler. PI. V, fig. 15. 
 
 Shell depressed, remarkably shining, brownish horn colour ; whorls 
 four and a half or five ; umbilicus large. 
 
 Helix lucida, Brown. Zonites lucidus, Gray. 
 
ZONITES. 29 
 
 This species is unmistakable when the animal and its 
 shell have not parted company,, for the former is quite 
 black, which is not the case with any of the other Zo- 
 nites, being generally of a greyish colour ; the shell too 
 is of a deeper hue and much brighter. It is similar to 
 Z. excavatus, in having a large umbilicus, but the latter 
 has a number of longitudinal striae, which are not found 
 in nitidus. From what we have collected we should 
 consider them gregarious. About a quarter of an inch 
 in diameter. 
 
 Hob. It chiefly inhabits marshy ground where it 
 may sometimes be found in great numbers, on the stems 
 of rushes and other aquatic plants, and on the tufts of 
 sedges which grow on the margin of ponds and streams. 
 It is pretty generally distributed, but somewhat local. 
 
 Z. EXCAVATUS. Bean. PI. V, fig. 16. 
 
 Shell depressed, small, shining, regularly striated, of a horn colour ; 
 umbilicus very capacious ; aperture orbicular lunate. 
 
 Helix excavata, Alder, fyc. 
 
 In form and appearance this shell comes nearest to 
 nitidus, but is of a lighter colour, has a larger umbili- 
 cus, and furnished with longitudinal striae, and not 
 nearly so lustrous. 
 
 Hab. This species is the least common of the Zonites, 
 perhaps owing to the nature of the habitats which it 
 frequents ; these are chiefly the roots of plants in woods, 
 and beneath fallen stems and trunks of trees which have 
 been for some considerable time on the ground. It is 
 always found, as far as we have been able to judge, in 
 districts where the Carboniferous formation is prevalent. 
 We have found it in woods near Wakefield, and have 
 had specimens sent from near Dewsbury and Penketh, 
 all in such districts, and it has been discovered near 
 Newcastle and Scarbrough. It is, we think, an illustra- 
 tion of the fact that Geological formations have much to 
 do with the distribution of animal life, especially in its 
 lower developments, not so much certainly as climate, 
 yet more than has generally been admitted. 
 
30 HELICID-H. 
 
 Z. CRYSTALLINUS. Midler . PL V, fig. 11. 
 
 Minute, nearly flat, glossy, a milky white colour, almost transpa- 
 rent ; mouth lunate ; umbilicus small. 
 
 Helix crystallina, Mull. 
 
 This is the smallest of the British Mollusks at present 
 comprised under the name Zonitcs, and is a sparkling 
 and perfectly transparent little gem. It may be dis- 
 tinguished from all the others by the closeness of the 
 whorls, which are also more numerous than those of 
 purus, which it most nearly resembles. The shell is 
 seldom more than an eighth of an inch in diameter. 
 
 Hdb. Almost every locality furnishes this species. 
 It is found in woods, hedge-rows, and mossy fields, 
 though seldom in very great numbers. Like most of 
 the other species it seems to prefer a damp to a dry 
 situation, and is frequently a little beneath the surface 
 of the earth. 
 
 HELIX. LinncBus. 
 
 Shell More or less spiral, globose or discoid ; outer lip thick- 
 ened ; variously coloured, without an epidermis ; mouth 
 lunated. 
 
 Ainmal With four tentaculce, an elongated depressed foot ; 
 tail lanceolate ; body produced and spiral. 
 
 H. APERTA. Born. PL VI, fig. 1. 
 
 Shell subglobose, thin, brownish green colour, somewhat wrinkled ; 
 mouth large and wide. 
 
 Helix naticoides, Drop, fyc. 
 
 In deference to the authority of Professor Forbes and 
 S. Hanley we retain this Helix as a British species. 
 Only one mutilated specimen has been discovered, and 
 that in the island of Guernsey, no doubt having been 
 brought over from France, in the south of which coun- 
 try they are abundant, and are eaten in Provence as 
 a delicacy. The above specimen is in the British 
 Museum. 
 
 Hob. Hedges amongst nettles. 
 
HELIX. 31 
 
 H. ASPERSA. Mutter. PI. VI, fig. 2. 
 
 Shell subglobose, brown colour with dark coloured bands ; whorls 
 four ; aperture ovato-lunate. 
 
 This most beautiful of British snails is very generally 
 distributed over England, Scotland, and Ireland, and 
 may be found at any time under stones, in holes in old 
 walls, and amongst the hedge-rows. During the win- 
 ter they collect in great numbers in sheltered nooks, 
 fastening themselves together so as to form a gregarious 
 mass of sometimes scores of individual specimens. The 
 process of hybernation may be best seen in this species 
 on account of its size and great abundance. (See Penny 
 Cyclopaedia). There is little fear of confounding this 
 with any other British species, though it varies consi- 
 derably in form and colour ; the prevailing colour is 
 chocolate, though we occasionally meet with specimens 
 almost entirely white. The mouth is white. When 
 irritated the animal emits a peculiar green mucus. 
 Sometimes used as food for pulmonary affections. An 
 inch and a half in diameter. 
 
 Hob. Found in all parts of the world. It is espe- 
 cially abundant in the neighbourhood of gardens. 
 
 H. POMATIA. Linnceus. PI. V, fig. 17. 
 
 Shell globose, solid, a tawny colour, with rufous bands, coarsely 
 wrinkled ; aperture roundish lunate. 
 
 This shell which is generally known by the appella- 
 tion of " the edible snail," is found in the south of 
 England, and is by some considered a dainty dish. It 
 is principally used as a substitute for animal food during 
 lent. The Romans were particularly fond of them, and 
 probably introduced them into this island from the 
 neighbouring continent, they had their cochlcaria 
 (snailleries), where they were regularly fattened with 
 new wine boiled down with meal, and probably grew 
 to a much larger size than those found now within our 
 limits, which live on a much scantier and plainer fare. 
 The diameter of a full grown specimen rarely exceeds 
 two inches. 
 
HELICID^. 
 
 Hab. The southern and midland counties of Eng- 
 land, upon cretaceous soils, principally in moss. 
 
 H. ARBUSTORUM. LinncBus . PL VI, fig. 5. 
 
 Shell nearly globular, spire more or less elevated ; a brown colour 
 beautifully marbled, marked with a single band ; outer lip white and 
 reflected. 
 
 This is one of the most elegant of our Helices. In 
 shape it approaches nemoralis, but is considerably higher 
 and blunter in the spire, with a much smaller mouth in 
 comparison to its size, the lip being also more reflected, 
 and generally extremely white and clear, forms a beau- 
 tiful .contrast with the darker colour of the shell. The 
 inimitable variety of stripes and spots which is seen on 
 its surface will readily distinguish it from the rest. The 
 shell also is thicker than most species. The variation 
 in size, shape, and colour, is very considerable, it is 
 most commonly of a dark chocolate brown mingled with 
 lighter shades, but in the dales of Westmorland they 
 are found of a light yellowish colour, still the distinctive 
 nature of the markings and the peculiar contour of the 
 shell is the same. We have found several specimens 
 with elongated spires, which we considered as mon- 
 strosities. About three quarters of an inch in diameter. 
 
 Hab. Generally distributed, throughout moist woods 
 and river sides, in most parts of the British Isles. 
 
 H. CANTIANA. Montagu. PL VI, fig. 9. 
 
 Shell slightly depressed, subglobose, rufous below and near the 
 mouth ; lip not so perceptible as in most of the species of this genus ; 
 umbilicus not large. 
 
 Helix Carthusiana, Drap., c. 
 
 This shell is pretty generally distributed over the 
 country, being found most abundant perhaps in Kent 
 and Sussex, frequently on the sand hills near the sea 
 shores, seeming to prefer the stunted grass and herbage 
 of such places, to the rank luxuriant vegetation of 
 woods and hedge-rows. It may readily be distinguished 
 from its congeners by its greater transparency, and 
 delicate roseate hue. The one most nearly resembling 
 
HELIX. oo 
 
 it is Carthusiana, which is much smaller; but need 
 never be mistaken for the young of Cantiana, since in 
 the latter case, the mouth would not be fully formed 
 until it arrived at its perfect development. About 
 three quarters of an inch in length. 
 
 Hob. The recorded localities are " districts around 
 London, and the south of the Thames." They are also 
 found locally abundant in the south of Yorkshire, near 
 Pontefract, near Thirsk, &c., and on the banks of the 
 Tees. 
 
 H. CARTHUSIANA. Mutter. PL VI, fig. 12. 
 
 Shell depressed, mouth marginated, with a white band ; whitish 
 horn colour ; umbilicus small. 
 
 Helix Carthusianella, Drap., fyc. 
 
 It is very local, being found only on the chalky 
 downs in the south of England, where it sometimes 
 congregates in great numbers, but seldom spreads over 
 a large area. In shape and appearance it most nearly 
 resembles Cantiana, but is not half the size, flatter in 
 spire, and of a more delicately pellucid, pinkish white. 
 Diameter about three eighths of an inch. 
 
 Hob. Chalky downs in the extreme east of Kent 
 and Surrey. 
 
 H. NEMORALIS. LinncBUs. PL VI, fig. 3. 
 
 Shell somewhat globose and depressed ; variously coloured, often 
 banded ; lip reflected, dark brown or black. 
 
 This is one of the most variable in colour of land 
 shells, it being difficult to say what is the most pre- 
 vailing hue. It is very abundant, and may be readily 
 distinguished from the succeeding species by the colour 
 of the lip being a dark brown approaching to black, 
 while hortensis is white. 
 
 Hob. Found abundantly in all parts of the British 
 Isles ; hedge-rows are their favourite resort. 
 
 H. HORTENSIS. Lister. PL VI, fig. 6. 
 
 Somewhat globular, thin and smooth ; generally of a light yellow 
 colour, with or without bands ; lip white. 
 
 This shell, unlike nemoralis, is very local. It also 
 differs from it in being smaller, not quite so convex, 
 
 D 
 
34 HELICID^E. 
 
 thinner, of a lighter polish, and having the outer lip 
 white, which is a never-failing characteristic. Shell 
 about three quarters of an inch in diameter. 
 
 Hob. Woods, hedges, and shady places. We have 
 never met with them except in limestone or sandy 
 districts. 
 
 H. HYBRIDA. Leach. PI. VI, fig. 4. 
 
 Globular, smooth, glossy, thin; of a purplish brown colour; lip a 
 subdued flesh colour. 
 
 This distinct species must have been confounded by 
 several naturalists with some of the many varieties of 
 nemoralis. It is invariably of a brownish pink colour, 
 not banded, and has a fleshy pink mouth. Some con- 
 chologists suppose it to be a hybrid between nemoralis 
 and hortensis, hence its name ; but there does not seem 
 much ground for such a supposition. 
 
 Hob. Under hedge-rows, probably only in lime- 
 stone districts. Locally abundant. Hackfall woods 
 near Ripon ; Hutton Rudby, Cleveland, &c. 
 
 H. PISANA. Mutter. PI. VI, fig. 8. 
 
 Shell white, with numerous interrupted brown bands, both longitu- 
 dinal and transverse, wrinkled ; mouth not large, usually pink edged. 
 
 This shell varies much in colour ; the bands are some- 
 times suffused almost over the whole surface, at other 
 times so indistinct as not to be easily detected. It is 
 generally half-an-inch or more in diameter, but varies 
 according to the situation in which it is found. 
 
 Hab. Locally very abundant, but is confined to the 
 south-west of England and the south of Ireland ; in- 
 habiting dry, sandy plains, near the sea. Tenby, and 
 St. Ives, in Cornwall, are recorded localities. 
 
 H. VIRGATA. Da Costa. PI. VI, fig. 10. 
 
 Shell white, with one or more brown bands, more or less perceptible ; 
 mouth red. 
 
 Helix variabilis, Lam., fyc. 
 
 If an illustration of the gregarious habits of some of 
 the mollusks is wanted, we could hardly furnish a better 
 example than H, rirgata; they always live in colonies, 
 
HELIX. 30 
 
 and are frequently so numerous, as almost to cover the 
 ground with, a mass of animal life. There are many 
 species that have the same congregating habits. It 
 is a variable shell both in size and appearance. Those 
 that most nearly resemble it are pisana and erice- 
 torum; the former however is larger, generally about 
 twice the size, and may be known by its roseate mouth, 
 and the beautiful checquered stripes that surround it ; 
 while the latter has a much flatter spire, and the aper- 
 ture smaller and more circular. This species seldom 
 attains to half-an-inch in diameter. The spire consists 
 of five whorls, round the base of which the brown 
 band generally winds. The lip is not reflected nor 
 much thicker than the rest of the shell. 
 
 Hal. Extremely abundant in chalk and limestone 
 districts, and in sandy places near the sea coast. 
 
 H. CAPERATA. Montagu. PI. VI, fig. 15. 
 
 Shell a brownish colour, striated ; outer whorls rather angular ; 
 mouth small and white. 
 
 Helix striata, Drap. 
 
 The name of this shell would seem to premise some- 
 thing beautiful, and we are not disappointed when we 
 find it, but are delighted with its simple elegance of 
 form, and chasteness of colour. There is no other shell 
 that can be confounded with it. The whorls form a 
 regular curve, and do not come to an apex, as most of 
 the other Helices. It varies but little in shape, though 
 considerably in colour; the prevailing hue is white, 
 with brown concentrated markings. About three- 
 eights of an inch in diameter. 
 
 Animal a dingy white colour. 
 
 Hob. Similar situations to H. virgata, may often be 
 met with in large numbers on the sand hills near the 
 sea. Locally abundant. 
 
 H. ERICETORTJM. Mutter. PI. VI, fig. 18. 
 
 Shell discoid ; white or light brown colour, generally banded ; 
 aperture round and small ; outer lip acute. 
 
 Helix Itala, Linn. 
 
 r. 2 
 
00 HELICID.E. 
 
 This shell may be classed with the former three, in 
 conjunction with which it is frequently found, as hav- 
 ing very much the same habits, and living in the same 
 localities. It is generally about three-fourths of an 
 inch in diameter, but varies in size, the average diame- 
 ter being little more than half an inch. The umbilicus 
 is large and deep. It may be distinguished from 
 virgata, in being much more depressed, having the 
 umbilicus much larger and deeper, distinctly exhibiting 
 the second and third whorls, and the outer volution 
 and mouth smaller and more cylindrical ; it is also 
 destitute of the rufous colouring within the lip of the 
 shell. 
 
 Hob. Limestone districts and sands near the sea. 
 Generally distributed. 
 
 H. OBVOLUTA. Midler. PL VI, fig. 21. 
 
 Shell orbicular, a light amber brown colour ; spire rather concave ; 
 umbilicus spread, deep ; lip reflected and white. 
 
 This shell does not resemble any of our other British 
 species in appearance, and it is questionable whether it 
 is really indigenous. The aperture is trigonal or foot 
 shaped, with a reflected white lip. It differs from 
 lapicida, which is perhaps its nearest ally, in being 
 smaller, of a different colour, having the whorls more 
 clearly defined and concave, and being neither keeled 
 nor much rounded at the circumference. The peculiar 
 shape of the mouth will readily distinguish it from any 
 of the other Helices. Diameter nearly half an inch. 
 Animal a dusky colour, head and tentacles black. 
 
 Hob. The only recorded localities in which this rare 
 shell has been found, are among moss at the roots of 
 trees in Ditcham Wood, near Brenton, Hants, and along 
 the chalk escarpment of the South Downs. 
 
 H. LAPICIDA. Linnceus. PI. VI, fig. 16. 
 
 Shell orbicular, depressed ; grey or pale rufous, with darker radia- 
 tion* ; sharply carinated at the circumference . 
 
 The peculiar traits in this shell are, the depressed, 
 and when taken together, regularly curved whorls, 
 
HELIX. 37 
 
 the outer one of which is very sharply carinatcd at the 
 circumference, the purplish rufous colour, and its 
 unpolished surface. Animal a dusky green colour, 
 with two dark streaks running down the back. 
 
 Hab. A widely-distributed species, though of ne- 
 cessity local owing to its habits. This is a shell not 
 only peculiar to limestone districts, but to the rocks 
 themselves, in the fissures of which it secretes itself 
 during the drought of summer, and it is only after a 
 period of settled wet weather that it can be found 
 abundantly, even in localities where it is known to 
 be numerous. We can well remember, when taking 
 an excursion in Wensleydale, being very much disap- 
 pointed at not finding them on the limestone rocks, 
 with the exception of one or two specimens, though 
 we knew they abounded there, a number having been 
 sent us from the same locality, together with the infor- 
 mation that they actually swarmed upon the rocks and 
 walls during the wet weather. It has been found on 
 limestone rocks, in Wensleydale, the south of Durham, 
 the south of Yorkshire, and on chalky rocks in the 
 south-east of England. 
 
 H. RUFESCENS. Pennant. PL VI, fig. 19. 
 
 Shell depressed, reddish horn colour, concentrically striated, slightly 
 carinated and white at the circumference ; umbilicus large. 
 
 This shell is generally diffused over England, prefer- 
 ing a chalky soil, where they grow to great perfection. 
 Those found in the north of England are more globular 
 and smaller, seldom being half an inch in diameter, 
 while the typical form, sometimes measures nearly 
 three quarters of an inch. Though the shell varies in 
 colour, it cannot well be confounded with any other 
 species. 
 
 Hab. Found in almost every district. Its favourite 
 place of resort, where there are no calcareous rocks, is 
 at the foot of a wall, where they no doubt derive some 
 of their necessary support. More common in the 
 south than the north of England. 
 
38 HELICIDJE. 
 
 H. HISPID A. Linnaeus. PI. VI, fig. 7. 
 
 Convex, reddish or brownish horn colour ; umbilicus moderately 
 large. 
 
 With the exception of some of the Pisidia, this is by 
 far the most difficult species to say what are its true 
 limits. Under the name are now included the three 
 distinct species of Gray, hispida, concinna, and depi- 
 lata. There is such a difference in the appearance and 
 thickness of the shell that it is very difficult to recon- 
 cile them as being the same species. The real hispida 
 may be readily distinguished by being thin, and having 
 the periojtraca hairy. It most nearly resembles sericea, 
 but is of a darker colour and rather more depressed ; 
 the animals also are quite distinct. 
 
 var. DEPILATA. Shell particularly hard, rather 
 smaller, of a horn colour, more depressed, peristome 
 thickened and of a whitish colour. 
 
 It seems to prefer a sandy situation, and is sometimes 
 very abundant on the hillocks near the sea coast. 
 
 var. CONCINNA. Shell more nearly approaching 
 hispida, and found in similar situations, it differs from 
 it however in having a thicker shell, larger umbilicus, 
 generally more depressed, and is destitute of hairs. 
 
 Hab. Woods, either under stones, or climbing up 
 plants and grasses. Common almost everywhere. 
 
 H. REVELATA. FeTUSSaC. PI. VI, fig. 22. 
 
 Shell globular, thin, diaphanous, shining, pale green colour, downy; 
 umbilicus small. 
 
 This shell is by no means common, having been 
 found in a comparatively few places. It is not quite 
 so large as sericea, which it most nearly resembles in its 
 general contour, though it may always be distinguished 
 by its peculiar green colour. About a quarter of an 
 inch in diameter. 
 
 Hab. The recorded localities are near Doyle's Mon- 
 ument in Guernsey, Torquay, Plymouth, and other 
 places in Devon and Cornwall. 
 
HELIX. 39 
 
 H. SERICEA. Draparnaud. PL VI, fig. 11. 
 
 Somewhat globular, transparent, yellowish horn or white colour, 
 closely downy ; six volutions ; umbilicus small. 
 
 Helix granulata, Gray, Brown. 
 
 This beautiful little shell may be readily distin- 
 guished from hispida, which it most nearly resembles, 
 in being a lighter colour, having the hairs finer and 
 more closely set, and the spire not nearly so much 
 depressed. The animal is greyish about the head and 
 tentacles, the mantle marbled with black. This species 
 includes sericea and granulata of Gray, which appear 
 to be but variations of the same shell, probably arising 
 from some natural or local circumstances. Diameter 
 the third of an inch. * 
 
 Hob. Found in similar situations to Jiispida; delight- 
 ing in luxuriant vegetation in damp woods, &c. The 
 species is widely distributed but local, we have met 
 with it abundantly in woods near Middleton-one-row, 
 Durham, and in Bilsdale, Cleveland. It is recorded as 
 being frequent in the south and west of England. 
 
 H. LAMELLATA. Jeffreys. PL VI, fig. 13. 
 
 Shell small, trochiform, with close set longitudinal lamellae ; mouth 
 lunate ; umbilicus deep. 
 
 The similarity between this species and fulva, is 
 greater than between it and aculeata, though perhaps 
 more properly speaking it holds an intermediate place 
 between the two ; the whorls are not so close as those 
 of fulva, and it is not so conical, being much blunter 
 in the spire ; moreover it is covered with longitudinal 
 ridges, and has a round instead of a flat bottom. About 
 the tenth of an inch in diameter. 
 
 Hob. This shell is far from common, having only 
 been found in few localities ; it prefers a damp situation 
 amongst decaying vegetable matter. It is confined to 
 the north of England, but generally distributed over 
 Ireland. We have found it in Airy Holme Wood, 
 Cleveland, and other places. 
 
40 HELICID^E 
 
 H. ACULEATA. Muller. PL VI, fig. 17. 
 
 Shell minute, rather trochiform ; four volutions, with spines around 
 the upper part of the middle of them. 
 
 This is much more common than the preceding, and 
 is found in somewhat similar localities, though it also 
 frequents drier situations. The beautiful rows of spines 
 with which this is fringed, are a peculiar and unique 
 feature, being dispersed in regular rows, and are very 
 large in comparison with the shell. The aperture is 
 nearly round. About the tenth of an inch in diameter. 
 Animal a peculiar grey colour. 
 
 Hab. Woods, among leaves and under stones. A 
 bunch of moss from a hedge bank will sometimes yield 
 a number of specimens. It is widely distributed, but 
 scarce in some localities. 
 
 H. FULVA. Muller. PL VI, fig. 14. 
 
 Shell small, trochiform, smooth and glossy ; dark horn colour. 
 
 This shell and the two preceding have many charac- 
 teristics in common, being all of them more or less of 
 a trochoid conical form, with but small apertures. 
 H. fulva differs from aculeata and lamellata in having 
 no spines ; being perfectly smooth and shining. The 
 whorls are so close and intimately connected as to give 
 the appearance of a perfect cone with a flat base. It is 
 somewhat larger than the former two, being about the 
 sixth of an inch in diameter. Animal grey with long 
 tentacles. 
 
 Hab. It is found in damp places upon stones at the 
 roots of grass and amongst dead and decaying vegetable 
 matter. Widely diffused. 
 
 H. FUSCA. Montagu. PL VI, fig. 24. 
 
 Shell subglobose, transparent, horn colour, wrinkled, very thin; 
 umbilicus narrow. 
 
 There is no other species with which this can be con- 
 founded, H. revelata approaches nearest in form, but is 
 much smaller and of a decidedly green colour, whereas 
 fusca is of a delicate straw yellow, exceedingly thin, 
 and moderately transparent. About three-eighths of 
 
HELIX. 41 
 
 an inch in diameter. Animal of a yellowish colour, with 
 dusky tentacles, the anterior ones being rather long. 
 
 Hob. It is one that loves a luxuriant vegetation, in 
 damp shady woods, where the undergrowth of ferns, 
 nettles, and plants, flourish in unrestrained profusion. 
 It is consequently local, there being few recorded locali- 
 ties, and these chiefly in the north. We have met with 
 it abundantly in Airy Holme Wood,* near Great Ayton, 
 and also in woods near Doncaster, &c. It is peculiar 
 to Britain. 
 
 H. PULCHELLA. Muller. PI. VI, fig. 20. 
 
 Shell minute, opaque white, depressed ; mouth nearly circular, with 
 the lip much reflected. 
 
 This little shell well deserves the name of " fair," for 
 though so small it is indeed a lovely gem, of a delicate 
 pellucid white colour ; its shape reminding us of the 
 Carocollce, which are found in warmer climates. The 
 large reflected outer lip is very peculiar and gives it an 
 elegant though unsymmetrical appearance, difficult to 
 describe. The umbilicus is large, exposing the upper 
 volutions. Animal white, upper tentacles long and 
 cylindrical. 
 
 var. COSTATA, which is grooved longitudinally, is by 
 many marked as a distinct species, but its characteristics 
 do not warrant any such separation. 
 
 Hob. It is by no means abundant, but is pretty 
 generally scattered over the country. Its most fa- 
 vourite resorts are rocks and stones, just beneath the 
 surface of the ground, where the roots of grass come in 
 contact with them. The variety is not so common as 
 the normal form, it is recorded as being most abundant 
 at Minching Hampton, near Exeter, on dry walls 
 amongst Sedum acre. 
 
 H. ROTUNDATA. Muller. PI. VI, fig. 23. 
 
 Shell depressed, deeply marked with striae, rufous, spotted with 
 chocolate ; umbilicus very large. 
 
 * For an account of the Land Shells found in this wood, see " The 
 Naturalist " for 1854. 
 
HELICID^E. 
 
 Helix radiata, Da Costa, Sfc. Zonites rotundatus, 
 Gray, fyc. 
 
 This common but pretty little shell, is found in almost 
 every locality, and cannot well be mistaken for any 
 other. Its most peculiar characteristic are the radiated 
 striae, which are very conspicuous. It is abundant in 
 almost every locality, being found in conjunction with 
 Zonites and Zua lubrica. By some conchologists, this 
 and the following have been classed with the genus 
 Zonites, but have more relations in common with the 
 Helices. Though the shells of H. rotundata are pretty 
 much of one shape and colour, they admit of one or two 
 distinct varieties, which are not so common as the nor- 
 mal species. 
 
 var. TUB/TON i, has the spire quite flattened. 
 
 Hob. At the roots of grass, or under stones, in 
 woods, fields or lanes. Abundant all over the British 
 Isles. A pellucid variety, translucens, is recorded as 
 having been found at Kenilworth Castle, and other 
 places ; it is by no means common. 
 
 H. UMBILICATA. Montagu. PI. VI, fig. 5. 
 
 Shell small, wrinkled, opaque, not smooth; aperture circular; outer 
 lip acute ; umbilicus very large. 
 
 Zonites umbilicatus, Gray. 
 
 This shell resembles the former in many points, but 
 is much smaller, has a more elongated spire, is not so 
 common, and is found in dry situations. It delights in 
 exposed places, such as the tops of houses or walls. 
 The spire varies, being more elevated in some than 
 others. They show a preference, but are not peculiar 
 to calcareous soils. The colour of the shell is very 
 similar to darker specimens of rotundata, as are also the 
 wrinkles or striae on its surface. Diameter about the 
 tenth of an inch. Animal dark grey, and polished. 
 
 Hob. Dry soils, on walls or buildings, in exposed 
 situations. Generally diffused over the British Isles, 
 and very abundant in some places. 
 
BULIMUS. 43 
 
 H. PYGMJEA. Draparnaud. PL VI, fig. 34. 
 
 Shell minute, rather convex, of a pale brown colour; umbilicus large. 
 
 Zonites pygmaeus, Gray. 
 
 This shell differs from the former in being smaller, 
 having the spire much more depressed, being more 
 transparent, and of a pale colour. It is like the former 
 marked with regular longitudinal striae. Whorls three 
 and a half to four, which are deeply defined. Diameter 
 less than one line. 
 
 Hob. There is every reason to believe this delicate 
 little shell is generally diffused over the British Isles ; 
 but on account of its being so very minute, and of a 
 colour generally resembling the soil it inhabits, it prob- 
 ably has been overlooked in many districts. Unlike 
 the former species, it delights in damp situations, 
 amongst dried leaves and decayed vegetable matter. 
 Often found at the roots of grass in a moderately damp 
 field. 
 
 We reject H. liinbata as spurious, on the authority 
 of Professor Forbes and S. Hanley. It is a continental 
 species. The few specimens which have been found, 
 were probably introduced with foreign plants. 
 
 BULIMUS. Scopoli. 
 
 Shell Spiral, oblong, unpolished, aperture oval, devoid of 
 
 teeth ; colwnella entire. 
 Animal Similar to that of Helix. 
 
 B. ACUTUS. Mutter. PI. VII, fig. 1. 
 
 Turreted, conical, white or clear brown, generally banded ; peris- 
 tome thin, scarcely reflected. 
 
 This beautiful turreted little snail is gregarious in its 
 habits, and locally distributed, being partially if not 
 exclusively confined to calcareous soils. It varies much 
 in colour, being sometimes nearly white and sometimes 
 a light brown, in both cases with the bands more or less 
 perceptible. It is very similar to virgata in its habits. 
 Indeed the distinction between the Bulimi and Helices 
 is nothing more than a little difference in the conform a- 
 
44 HELICID^E. 
 
 tion of the shell. Length usually about half an inch. 
 Animal yellowish, with four tentacles, upper one long. 
 
 Hal). Extremely abundant in the west and south of 
 England, on chalk or sandy maratime pastures. It is 
 also recorded as having been found on the Isle of Man, 
 in the west of Scotland and Hebrides, and many parts 
 of Ireland. 
 
 B. LACKHAMENSIS. Montagu. PI. VII, fig. 2. 
 
 Shell oblong, chocolate brown colour ; mouth sub-oval. 
 Bulimus montanus, Brown, fyc. 
 
 This fine Bulimus, which is found only in the south 
 of England, is probably, like the former species, confi- 
 ned to the chalk and limestone formations. It is one of 
 our rarest land shells, having been found in compara- 
 tively few localities. The equal coating of chocolate 
 brown colour, together with its size, about five-eighths 
 of an inch in length, and spiral appearance, readily 
 distinguish it. The animal resembles that of obscurus. 
 
 Hal. Wooded districts in the south of England, on 
 the lime and chalk formation, frequently on the stems 
 of trees, beech trees in particular, or under decayed 
 leaves at their roots. Essex, Kent, Wiltshire, Somer- 
 setshire, and many localities near Cheltenham, are 
 recorded. 
 
 B. OBSCURUS. Mutter. PI. VII, fig. 3. 
 
 Shell similarly shaped to the last, but smaller ; brownish horn colour; 
 peristome white, reflected. 
 
 Helix bbscura, GmeL, fyc. 
 
 This shell closely resembles the preceding species, 
 but is smaller, being little more than three lines and a 
 half long ; the volutions are somewhat more rounded, 
 the mouth shorter, and peristome white. The colour 
 is much lighter and devoid of the dark brown or choco- 
 late hue. The greatest peculiarity about this shell is 
 that it envelopes itself with a coating of mud, seemingly 
 for the purpose of escaping detection ; hence its name 
 " obscurus," When it is found on the trunks of trees, 
 
PUPA. 46 
 
 the colour of its coat generally partakes of that of the 
 part it is on. The animal is very similar to the pre- 
 ceding. 
 
 Hab. Hedges, amongst dead leaves, under stones, 
 &c. ; and in woods, frequently on the stems of trees. 
 It is widely diffused, being found more or less abun- 
 dantly in all parts of the British Isles. 
 
 The spurious species B. Goodalli, B. decollatus, and 
 B. clavulus, have been introduced by some naturalists 
 into the British Fauna, from living specimens having 
 been found in pine-beds, warmed by artificial heat, at 
 Bristol, Exeter, and other places. 
 
 PUPA. Lamark. 
 
 Shell Spiral, more or less cylindrical, abruptly obtuse ; 
 whorls numerous and close ; mouth mostly toothed 
 within, peristome reflected. 
 
 Animal Short, four tentacles, the upper ones developed, the 
 lower ones short, sometimes hardly discernible. 
 
 P. UMBILICATA. Draparnaud. PI. VII, fig. 4. 
 
 Cylindrical, brownish ; mouth lunate, provided with one tooth ; 
 peristome much reflected. 
 
 This is the commonest, though by no means the least 
 attractive of the Pupae; its little ivory white lip forming 
 a beautiful contrast with the body of the shell, which is 
 of a dark chocolate colour, and polished. It approaches 
 nearest in form to muscorum, being about the same 
 size, and having, a single tooth on the pillar ; but differs 
 in having the whorls more loosely set, and more inclined 
 to the axis. The peristome too, is not only thickened 
 but reflected ; whilst the lip of muscorum, although 
 thickened is not reflected. It is also a brighter colour, 
 and somewhat pellucid. The animal is of a lead colour 
 above, and white beneath ; the upper tentacles long, 
 lower ones short but distinct. 
 
 Hab. This shell is very plentiful ; inhabiting chiefly 
 woods and hedge-rows, among the roots of grass or dead 
 
46 
 
 HELIClDvE. 
 
 leaves. Another favourite habitat are the fissures found 
 in the bark of such trees as the oak, where it may be 
 sometimes found in considerable numbers, clustered 
 together ; the moss and lichen which cover them may 
 also often be searched with success. It is a widely dis- 
 tributed species, and found in all parts of the British 
 Isles. 
 
 P. MUSCORTJM. Linnceus. PI. VII, fig. 5. 
 
 Shell, cylindrical, yellowish brown or chestnut colour ; outer lip noi 
 reflected, but margined by a strong external rib. 
 
 Pupa marginata, Drap., fyc. 
 
 There is very little difference between this and th< 
 former species, as noticed above ; the chief point o- 
 distinction is in the outer lip, which is here curiously 
 marginated by a strong rounded callus or rib. The 
 spine consists of six or seven volutions ; the basal one 
 is not so much extended as in umbilicata. The shell 
 is moderately strong, not diaphanous or shining, of a 
 yellow or brown colour, and slightly striated. Animal 
 greyish black, white underneath, lower tentacles very 
 short. 
 
 Sdb. It is often found in similar localities to the 
 last, but may be also found in dryer situations, on 
 sands near the sea, or calcareous soils. It is widely 
 distributed. 
 
 P. ANGLICA. Ferussac. PI. VII, fig. 6. 
 
 Shell dextral, shining dark brown approaching to black ; peristome 
 flatly reflected ; mouth with fine teeth. 
 
 This beautiful little shell is somewhat smaller than 
 the preceding, and may be readily distinguished from 
 them by having its mouth thickly set with five little 
 threatening teeth. Its colour also is much darker, being 
 almost black. The aperture is something of the shape 
 of the lobe of the human ear. Animal dark lead 
 colour above, white beneath. 
 
 Hal. It is quite a local shell, and may almost be 
 considered rare, having only been found in a few places 
 
PUPA. 47 
 
 in the north of England and part of Ireland. Scarbro', 
 near Newcastle, Airy Holme Wood in Cleveland, 
 and Hackfall Woods near Ripon, are some of the re- 
 corded localities. It seems to delight in deep, shady, 
 somewhat boggy and peaty woods, living amongst the 
 rankly growing weeds, which flourish upon soil formed 
 from decomposed vegetable matter. 
 
 P. SECALE. Draparnaud. PL VII, fig. 7. 
 
 Shell rather cylindrical, dextral, brown ; aperture with seven or 
 eight teeth ; peristome acute. 
 
 Pupa juniperi, Gray, fyc. 
 
 This largest of the Pupa genus is found almost ex- 
 clusively in the south of England, and is readily distin- 
 guished both from its size and the number of laminar 
 teeth within the aperture. Of a dull brown or pale 
 chocolate brown colour. Whorls from seven to nine 
 in number. It generally measures about a quarter of 
 an inch in length. Animal blackish brown above, pale 
 beneath. 
 
 Limestone localities in the south of England. 
 Headington Quarry near Oxford, and limestone in the 
 neighbourhood of Kendal. Roots of trees and under 
 stones, &c. 
 
 P. EDENTULA. Draparnaud. PI. VII, fig. 8. 
 
 Minute, dextral ; mouth toothless ; peristome simple, not reflected. 
 Vertigo edentula, Gray, Sfc. 
 
 This Pupa may be readily distinguished from the 
 other by the number of volutions, which in full grown 
 specimens are six or seven in num.ber, and its cylindri- 
 cal shape, in which characteristic it closely resembles 
 minutissima, from which it may be distinguished 
 by its greater size. The lip has no external rib or 
 callus, nor is it at all reflected. The shell is transpa- 
 rent, of a light horn colour, very thin and somewhat 
 polished. Length rather more than the tenth of an 
 inch, and height about one third the length. The 
 animal is grey above but lighter beneath. 
 
48 HELICIDJE. 
 
 Hab. Damp places at the roots of grass, under 
 stones, &c. It is widely diffused, but rather local. 
 This, together with the remaining members of the 
 Pupa genus, may have been overlooked on account of 
 their being so minute, and their colour so often resemb- 
 ling that of the soil, leaves, &c., on which they may 
 be found. Plentiful in many parts of Yorkshire and 
 Durham. 
 
 P. MINUTISSIMA. Hartmann. PI. VII, fig. 9. 
 
 Shell minute, cylindrical, dextral, a pale brown colour, wrinkled ; 
 mouth edentulous ; lips scarcely reflected. 
 
 Pupa muscorum, Drap. Vertigo cylindrica, Gray. 
 
 With the exception of Venetzii, this is the rarest of 
 our British Pupae. It may easily be distinguished by 
 its minute size, not measuring more than one line in 
 length, by two-fifths of a line in breadth, and cylin- 
 drical shape. Whorls five or five and a half, much 
 rounded ; suture abrupt. The animal is dark, streaked 
 with black and shining. 
 
 Sab. There is every reason to believe this some- 
 what rare Pupa is generally diffused through the 
 British Isles. It seems partial to calcareous rocks, and 
 the debris at their base may often be searched with suc- 
 cess. The reported localities are Balmenna, Fifeshire, 
 Durdham Downs near Bristol, and Salisbury Crags, 
 Edinburgh. We have also found it pretty abundantly 
 in conjunction with pusilla, edentula, substriata, py- 
 gmcea, and many commoner shells, upon the top of the 
 magnesian limestone crags, Went Vale near Ackworth. 
 
 P. PYGM^A. Druparnaud. PI. VII, fig. 10. 
 
 Shell minute, dextral, ovate ; whorls four to five ; mouth with four 
 or five teeth ; peristome marginated externally. 
 
 Vertigo pygmsea, Gray, Sfc. 
 
 In shape and external characteristics, this little shell 
 somewhat resembles substriata, but the latter is more 
 conical, and has six teeth ; it is also rather less. The 
 
PUPA. 49 
 
 peristome of pygmcea is slightly thickened and re- 
 flexed. Animal dark grey, upper tentacles small, lower 
 ones almost obsolete. 
 
 var. ALPESTRJS, Forbes and Hanley, has only four 
 teeth, it may also be distinguished by its lighter colour- 
 ing, and more cylindrical shape. 
 
 Hob. Widely distributed, and in some places abun- 
 dant ; under stones, decayed leaves, &c. The variety 
 has, as yet, been found only in the northern counties. 
 
 P. SUBSTRIATA, Jeffreys. PL VII, fig. 11. 
 
 Shell minute, dextral, striated ; mouth with six teeth (only four 
 easily perceptible); yellow horn colour. 
 
 Vertigo substriata, Gray. Turbo sexdentatus, Mont. 
 
 This minute shell is more conical than the preceding, 
 and longitudinally striated. The volutions, four or five 
 in number, are well rounded and rather high. It may 
 be distinguished by being the smallest of the tribe, 
 and having the two parietal teeth very perceptible. 
 Animal blackish grey. 
 
 Hob. Like most of the other shells of this genus, 
 particularly the Vertigo section of them, it seems to be 
 widely distributed, but often overlooked on account of 
 its diminutive size, &c. Among wet moss or grass, 
 in marshy places. The principal localities in which it 
 has been found are in the north of England, but Nor- 
 folk and Devonshire are also recorded districts. We 
 have observed it among peaty soil, on magnesian lime- 
 stone rocks in the south of Yorkshire. 
 
 P. ANTIVERTIGO. Drapamaud. PI. VII, fig. 12. 
 
 Shell dextral, minute, shining brown, with five volutions ; mouth 
 trigonally lunate, with from seven to nine teeth. 
 
 Vertigo palustris, Gray. 
 
 This beautiful little Pupa is easily distinguished from 
 the rest ; firstly by its shining dark chocolate colour, 
 with the extreme margin of the aperture whitish ; 
 secondly by its teeth, three of which are very promi- 
 nent and easily perceived, they are of unequal size ; 
 
50 HELICIDJE. 
 
 and thirdly by the peculiar localities which it frequents. 
 The whorls are five in number, quickly enlarging, 
 which gives it an oval, or irregular spindle shape. 
 Animal dark, shining ; upper tentacles thick and short, 
 lower ones almost imperceptible, mere dots. 
 
 Hob. Marshes and other wet places ; the muddy 
 sides of slow streams, canals, &c. It is widely distri- 
 buted, rather local, but sometimes plentiful. It has 
 been found near Swansea, Bath, Bristol, Cheltenham, 
 &c. ; also near Oxford and many places in the south of 
 England. 
 
 P. PUSILLA. Mutter. PL VII, fig. 13. 
 
 Shell cylindrical, minute ; mouth sinistral, with six to eight teeth ; 
 peristome thin. 
 
 Vertigo pusilla, Gray. 
 
 By being sinistral this shell is at once distinguished 
 from the remainder of the genus, except Venetzii, from 
 which it may be distinguished by being much larger, 
 and having the aperture larger, and of a semi-oval 
 shape. Pusilla is transparent, glossy, and of a pale 
 chestnut colour. The mouth is armed with six or 
 seven teeth, and one is sometimes appended to the 
 pillar lip. Animal dark grey, pale underneath. 
 
 Hob. Among damp moss, under stones, &c. It is 
 widely diffused, and in some places pretty abundant. 
 Walls at Woodeaton, near Oxford, and many other 
 districts in the southern and eastern counties ; Went 
 Vale, near Ackworth, and other localities in Durham, 
 Northumberland, and Westmoreland. Rare in Ire- 
 land. 
 
 P. VENETZII. Charpentier. PL VII, fig. 14. 
 
 Shell very minute, sinistral, pale amber colour, teeth four or five. 
 Vertigo aiigustior, Gray. Turbo vertigo, Mont. 
 
 This rare shell has only been discovered in a few 
 localities, in the British Isles. It is very minute, thin, 
 and not shining. Its little, short, thick-set whorls, 
 
DA LEA. 51 
 
 which are abruptly terminated at the apex and con- 
 tracted at the base, give it a peculiar barrel-like 
 appearance. The mouth is very small and of a 
 curious subtriangular shape. We have not seen a 
 living specimen of this shell, nor any description of 
 the animal. 
 
 Hdb. The recorded localities are the rejectment of 
 a small stream at Merino, near Swansea, Cork, and 
 Miltown Malbay in Clare. We have also found it 
 amongst the rejectment of a small stream running into 
 the Tees, near Norton. 
 
 BALEA. Prideux. 
 
 Shell Sinistral, regular, elongated, tapering, oval; spire 
 resembling Clausilia, but has no clausium ; a single 
 tooth, on the pillar. 
 
 Animal Resembling Bulimus. 
 
 B. FRAGILIS. Draparnaud. PL VII, fig. 15. 
 
 Turbo perversus, Linn. Pupa fragilis, Drap. Clau- 
 silia fragilis, Jeff. Balea perversa, Gray. 
 
 This genus is intermediate between Pupa and Clau- 
 silia; from the former it differs in the unequal margin 
 of the mouth, and from the latter in having no clausium, 
 and the last whorl larger than the others. From 
 Bulimus it differs in having the aperture sinistral. It 
 is semi-transparent, and of a yellow olivaceous colour. 
 Whorls six or seven, slanting regularly to the apex, 
 which is rather acute. This shell closely resembles 
 the young of Clausilia nigricans, but may be distin- 
 guished from it by having the last whorl convex, not 
 flattened or keeled. Aperture pyriform. About the 
 third of an inch in length. Animal dark grey, rather 
 mottled. 
 
 Hob. Found in all parts of the British Isles ; on the 
 trunks of trees, sometimes under moss, lichens, &c., 
 which are attached to walls. It is probably one of the 
 many shells which prefer limestone districts. 
 
 E 2 
 
HELICID^. 
 
 CLAIJSILIA. Draparnaud. 
 
 Shell Spiral, produced, the last volution less turned than 
 the one before it, sinistral ; aperture pyriform, toothed ; 
 throat closed by an internal testaceous plate or clausium. 
 
 Animal Short ; upper tentacles stout, lower ones very small. 
 
 The great peculiarity in these shells is the clausium, 
 which is thus described by Gray. " It consists of a 
 spirally-twisted thin shelly plate, inclosed in the last 
 whorl of the shell. When the animal is retracted 
 within its shell, this shelly plate nearly covers the aper- 
 ture at a little distance within the mouth, and coming in 
 contact with a transverse plait on the outer lip, leaves 
 only a small canal formed between the outer plait and 
 the posterior angle of the mouth, and sometimes an 
 elongated longitudinal plait on the inner lip. When 
 the animal wishes to protrude itself, it pushes the plate 
 on one side into a grove situated between the inner 
 plait and the columella, where it is detained by the 
 pressure of the body of the animal, leaving the aper- 
 ture free ; and when the animal withdraws itself, the 
 plate springs forward by the elasticity of the pedicle 
 and closes the aperture." 
 
 C. LAMINATA. Montagu. PI. VI, fig. 27. 
 Shell large, nearly smooth, glossy, and serai-transparent. 
 Clausilia bidens, Gray., 8fc. 
 
 This large Clausilia sometimes measures three quar- 
 ters of an inch in length. The shell is generally of a 
 brownish colour and smooth, except at the base of the 
 last whorl, which is slightly striated. Transparent 
 greenish white specimens are sometimes, though rarely, 
 to be met with. Whorls ten, slightly convex ; the 
 suture is distinct but not deep. The peristome thick 
 and whitish, not reflexed, of a pyriform shape ; the 
 upper plate is small and straight, the under one, which 
 is in the middle of the pillar lip, curved. The animal 
 brownish, the upper tentacles clavate. 
 
 Hob. This shell is more common in the south than 
 
CLAUS1LIA. 53 
 
 in the north of England. It shows a great partiality to 
 beech woods, living among the decayed leaves of that 
 tree, and may sometimes be found on the trunk of the 
 tree itself. 
 
 C. BIPLICATA. Montagu. PL VI, fig. 28. 
 
 Shell ventricose, dark greyish brown, with regular longitudinal 
 striae ; aperture with two plates. 
 
 Clausilia ventricosa, Jeff., 8fc. 
 
 The regular raised striae at once distinguishes this 
 shell from the former, which it most nearly resembles 
 in other particulars. The spire consists of from ten to 
 twelve depressed, convex, but well-defined volutions ; 
 aperture sub-pyriform, with two plates, and sometimes 
 one or two additional denticles. It is about two thirds 
 or three quarters of an inch in length. 
 
 Hob. This beautiful Clausilia is confined to the 
 south of England, inhabiting woods and hedges near 
 London ; it has also been found at Bristol. It is prob- 
 ably confined to the chalk districts. By no means 
 common. 
 
 C. PLICATULA. Draparnaud. PL VI, fig. 29. 
 
 Shell ventricose, thin, opaque ; with regular longitudinal raised 
 striae ; aperture containing four or five plates. 
 
 Clausilia Rolphii, Gray. 
 
 This rare Clausilia may be distinguished from bipli- 
 cata by its reddish chocolate brown colour, and by the 
 plates within the aperture. The costella striae are fine 
 and only slightly raised. Whorls ten to twelve, moder- 
 ately well defined, but not particularly convex. From 
 three-fifths to three quarters of an inch in length. 
 Animal dark grey, upper tentacles thick and clavate. 
 
 Hob. First discovered by Rolph, in Charlton 
 Wood, Kent. It has since been found in other locali- 
 ties in Kent; also near Hastings, in Hampshire, Dove- 
 dale, in the Marsh, Gloucestershire, and Birdlip to 
 Cooper's Hill, near Cheltenham. It prefers damp 
 situations at the root of Mercurialis perennis, saxi- 
 fraga oppositifolia and other plants, on a chalky soil. 
 
54 HELICID^E. 
 
 C. NIGRICANS. Maton and Rackett. PL VI, fig. 30. 
 
 Shell slender, opaque, dark brown ; five more or less raised, some- 
 what granular, striae ; mouth with three plates, margin white. 
 
 Clausilia rugosa, Brown. 
 
 This is by far the commonest of our British Clausilia, 
 being abundant almost everywhere. It may readily 
 be distinguished from the others by being so much less, 
 seldom attaining half-an-inch in length. It is nearly 
 opaque with a dark brown lustre, often marked with 
 whitish streaks. The spire is composed of from seven to 
 eleven moderately convex volutions. Aperture small 
 and pyriform. 
 
 var. DUBIA, (Plate VI, fig. 31,) is somewhat larger, 
 more ventricose ; the stria? broader and more raised. 
 
 Hob. Plentiful in almost every locality in the 
 British Isles. It may be found under stones on walls 
 and rocks (particularly limestone), in the earth or even 
 on trees. The variety occurs in the north-east of 
 England. Tanfield, near Eipon, Haughton-le-spring, 
 near Sunderland, &c. ; it has been found as far south 
 as Oxford. 
 
 ZUA. Leach. 
 
 Shell Spiral, rather cylindrical, Hunt, smooth and polished ; 
 mouth ovate ; peristome toothless, thicJeened but not 
 reflexed. 
 
 Animal Allied to and closely resembling Bulimus. 
 Z. LUBRICA. Mutter. PL VI, fig. 32. 
 
 Helix lubrica, Mont. Bulimus lubricus, Brown. 
 
 At first sight there is a considerable likeness between 
 this species and Azeca tridens, but its lighter colour, 
 slender shape, and more prominent whorls will readily 
 distinguish it ; besides the never-failing characteristic, 
 the mouth, which in this shell is almost oval, quite 
 plain, and not furnished with projections as in A. tridens. 
 This genus is distinguished from Bulimus by its pol- 
 ished periostraca. The shell varies in size and colour, 
 though .generally an olivaceous brown; it is highly 
 
A/ECA. 55 
 
 polished and transparent. Length a quarter of an inch. 
 Animal dark grey above, lighter underneath, upper 
 tentacles nearly black, and clavate. 
 
 Hal. It has a very wide distribution, and may 
 be found in almost every situation where vegetation 
 of any kind flourishes. Fields, hedge-rows, woods, 
 and waste places, amongst the roots of grass or moss, 
 stones, or buried an inch or two in the earth. Very 
 abundant. 
 
 AZECA. Leach. 
 
 Shell Spiral, sulcylindrical, smooth, remarkably shining; 
 aperture pyriform ; peristotne entire, thick and toothed, 
 not reflexed. 
 
 Animal Like that of Zua. 
 
 A. TRIDENS. Pulteney. PL VI, fig. 33. 
 Turbo tridens, Mont. 
 
 Shell ovate, cylindrical, firmer than the preceding, 
 brightly polished and of a reddish brown colour; smooth, 
 with the exception of a few wrinkles near the suture. 
 "Whorls seven or eight and much depressed. Mouth 
 small and pyriform, guarded by three prominent teeth, 
 sometimes two additional small ones intervening. It 
 may readily be distinguished from its congeners by its 
 shining barrel-like form, with whorls scarcely projec- 
 ting at all, and its contracted mouth protected by 
 threatening teeth. Length about a quarter of an inch. 
 Animal dark. 
 
 Hob. This pretty little shell is generally distributed 
 over the country, and though by no means uncommon, 
 is much more local than the preceding. Its usual 
 habitat is amongst the damp and luxuriantly growing 
 vegetation of woods. It is one of the mollusks which 
 seem to live in colonies, so that the collector may be 
 pretty certain when he finds one or two specimens, that 
 there are a number not far distant. It has not yet been 
 found in Ireland. 
 
56 HELIC1DJE. 
 
 ACHATINA. Leach. 
 
 Shell Spiral, elongated ; mouth ovate or elongated ; peris- 
 tome thin, never reflexed. 
 
 Animal Closely resembling that of Bulimus. 
 
 A. ACICULA. Mutter. PL VII, fig. 16. 
 Bulimus acicula, Drap., fyc. 
 
 Shell about a quarter of an inch long, tapering, acute 
 at the apex, narrow in proportion to the length. Outer 
 margin of the lip thin, not reflexed, of a uniform white 
 colour, smooth and polished. Pillar smooth, simple, 
 curved and truncated in front. Animal white, upper 
 tentacles cylindrical, not thickened at the extremity, 
 and deprived of eyes. This genus approaches in form 
 and appearance to the Bulimus^ but may be distin- 
 guished from it by the mouth being at least half the 
 length of the entire shell. They are a most interesting 
 genus, many of those found in tropical countries attain 
 to a large size, so that we can have little idea of them 
 from their tiny representative in the British Isles. 
 
 U.ab. This delicate shell delights in a sandy soil, 
 taking up its quarters among the roots of grass. The 
 downs and hillocks near the coast may be frequently 
 searched with success. After a considerable flood we 
 once found them in great abundance amongst the re- 
 jectment of the river Tees, near Middlesbro', whence 
 they had been brought from the banks of the stream 
 higher up. Living specimens are comparatively rare. 
 In many places it must be regarded as subfossil ; it ap- 
 pears to have abounded in Britian at the close of the 
 tertiary epoch. 
 
 SUCCINEA. Draparnaud. 
 
 Shell Oblong, oval, thin, spire conical, body whorl very 
 large ; mouth oblong ; peristome thin ; pillar smooth. 
 
 Animal Large, upper tentacles short and reflexrd, lower 
 ones very short. 
 
SUCCINEA. .57 
 
 S. PUTRIS. Linnceus. PI. VII, fig. 18. 
 
 Oblong, reddish amber colour, spire consisting of three whorls, 
 small ; aperture oblique. 
 
 Helix putris, Mont. Succinea amphibia, Drap. 
 Succinea gracilis, Brown, fyc. 
 
 Naturalists have found some difficulty in describing 
 and affording limits to the species under this genus, 
 especially in regard to this particular member. It com- 
 prises, under the present arrangement, two distinct 
 species of Gray, S. putris and Pfeifferi, as it is con- 
 sidered that the localities in which they are found, have 
 sufficient influence on their nature to account for the 
 difference between them. The shell of the normal form 
 is large, sometimes attaining three quarters of an inch 
 in length ; the colour varies from a rufous amber to a 
 pale yellow. The surface is glossy and more or less 
 wrinkled. Animal grey, spotted ; tentacles rugose. 
 On account of the diversities of form, &c., which this 
 shell assumes, is has been split up into many varieties. 
 
 var. AMPHIBIA is more compressed, and has the 
 sutures more oblique. The whorls, scarcely three in 
 number, are flattened above and rounded below, the 
 apex being very minute. Fine specimens are about 
 half-an-inch in length. 
 
 The other forms are gracilis, oval, more or less 
 swollen, of a more pallid and less rufous colour than 
 the preceding. Its whorls typically much rounded ; 
 its sutures not peculiarly oblique : and its spire never 
 elongated. Intermedia presents the modified peculi- 
 arities of the preceding extreme forms ; there are three 
 and a half coils, so that the spire is occasionally more 
 elongated in proportion than gracilis or amphibia. 
 
 Hob. Abundant in almost every locality. S. Putris 
 inhabiting damp woods and meadows, while amphibia 
 prefers a still damper situation, and is never found 
 except on aquatic plants and mud by the sides of slow 
 running streams, ditches, &c., frequently immersed 
 in the water. 
 
58 LIMNJEAD^E. 
 
 S. OBLONGA. Draparnaud. PL VII, fig. 19. 
 
 Shell ovate ; whorls three or four, produced, ventricose ; aperture 
 ovate. 
 
 This rare British Succinea, may be readily distin- 
 guished from putris, by being much smaller, seldom 
 measuring more than a quarter of an inch in length, 
 having the spire more produced, and the aperture 
 nearly oval, and about equal to the spire in length. 
 Animal blackish grey, with paler thick set tentacles. 
 
 Hab. Edge of ditches, &c. It was found near 
 Swansea, but we have been told that it is now extinct 
 in that locality ; the only place in which it appears to 
 have been found in England is at " Topsham, Exeter, 
 three or four specimens in salt water marshes." It 
 has been found in several places in Ireland, and near 
 Glasgow, in Scotland. Sometimes found in superficial 
 deposits, half fossilized. 
 
 LIMNJEADJE. 
 PHYSA. Draparnaud. 
 
 Shell Thin, spiral, sinistral, polished ; moutli oblong. 
 Animal Tentacles long, with eyes at their bases. 
 
 The British species of this genus have been formerly 
 referred to two genera, Physa and Aplexus. The 
 animal of the former has a dilated mantle with lobed 
 edges ; that of the latter has a simple mantle. 
 
 P. FONTINALIS. Linnceus. PL VII, fig. 80. 
 
 Shell oval, horn coloured ; spire very short and obtuse ; aperture 
 much dilated. 
 
 Bulla fontinalis, Linn., fyc. 
 
 This pretty shell which is commonly called " The 
 Bubble Shell," is common throughout the greater part 
 of the British Isles. It varies much in form, and has 
 been separated into a great many varieties by some 
 naturalists. It may be easily distinguished by its 
 exceedingly small spire, its regular oval form, its thin 
 glossy and almost smooth exterior, together with its 
 yellowish horn colour. It often attains to the third of 
 
PHYSA. 59 
 
 an inch in length, the breadth being nearly one-fourth. 
 Animal lighter or darker grey, with long slender tenta- 
 cles of a paler colour. 
 
 var. ACUTA is larger and narrower, with a more elon- 
 gated spire. This variety is by no means common. 
 The variety 2 of Gray has the last whorl rather angu- 
 lar behind, it is smaller than the normal form, and 
 recorded as being found " in very small plashes of 
 water or in water among grass." The difference 
 of situation is probably sufficient to account for the 
 variations. 
 
 Hob. Streams, pools, &c., on aquatic plants in all 
 parts of the British Isles. 
 
 P. HYPNORUM. Linnaeus. PL VII, fig. 26. 
 
 Shell oblong, conical ; spire elongated and acute ; aperture oval 
 lanceolate. 
 
 Bulla hypnorum, Mont. Aplexus hypnorum, Gray. 
 
 This shell is in many respects similar to the preced- 
 ing, but differs from it in having a more elongated 
 spire, the last volution of which is not so ventricose. 
 The whorls are depressed, glossy, and transparent. 
 Aperture lanceolate ovate. About half-an-inch in 
 length, and one-fifth of an inch in breadth. Animal 
 nearly black, foot long and lanceolate. 
 
 Hal. Ditches, ponds, and slow running streams 
 throughout the British Isles, except the extreme north 
 of Scotland. It is as common, though somewhat more 
 local than the preceding. 
 
 PLANORBIS. Midler. 
 
 Shell Spiral, discoid, dextral ; aperture lunate, margin en- 
 tire ; peristome simple, neither thickened nor reflexed. 
 
 Animal A broad head with two tentacles, having eyes at 
 their inner bases ; foot small. 
 
 P. CORNEUS. Linnceus. PL VII, fig. IT. 
 
 Shell large, nearly flat above, deeply umbilicate beneath ; whorls 
 five, wrinkled, deeply divided, convex above, flattened beneath ; aper- 
 ture semicircular. 
 
60 LIMNJEAD^E. 
 
 Helix cornea, Mont., fyc. 
 
 This largest of our British Planorbes cannot possibly 
 be confused with any other on account of its superior 
 size, often measuring one inch in diameter, and one- 
 third of an inch in height. The shell is strong, 
 generally of a rusty brown or olivaceous yellow colour; 
 it is closely and obliquely striate. The animal is nearly 
 black, and when irritated gives out a purple fluid. 
 
 Hob. This elegant shell seems to hold a similar posi- 
 tion among the Planorbes, to that of H.pomatia among 
 the Helices, both being considerably larger than any 
 other species belonging to the same genus. It is abun- 
 dant in canals, ponds, slowly-running streams, &c., in 
 all parts of the south of England, with the exception 
 of Cornwall and Devon. It is recorded as having been 
 found as far north as Darlington. It occurs in one or 
 two localities towards the south of Yorkshire and Lan- 
 cashire. It has been found in Ireland. 
 
 P. ALBUS. Mutter. PI. VII, fig. 27. 
 
 Shell small, white or nearly so; slightly convex on both disks, 
 whorls nearly striated and pilose. 
 
 Planorbis hispidus, Drap., fyc. 
 
 This pretty little shell may be instantly detected 
 when quite fresh by its downy appearance, being 
 covered with minute hairs, which fall off with the epi- 
 dermis. It is the only British fresh-water species that 
 is at all hispid. The shell is thin, not much polished ; 
 the upper surface a little sunk in the middle, the lower 
 still more concave; rather angularly rounded at the 
 periphery ; about a quarter of inch in diameter. 
 Generally a pale horn colour, but sometimes, particu- 
 larly old specimens, more or less white. Animal a 
 pale grey, but varies in different localities. 
 
 Hob. Stagnant waters upon aquatic plants, Pota- 
 mogeton in particular. It is widely distributed, and 
 may be found more or less sparingly in almost every 
 locality. We have met with them occasionally in 
 several stells, in the neighbourhood of Ayton. 
 
PLANORBTS. 61 
 
 P. GLABER. Jeffreys. PL VII, fig. 21. 
 
 Shell small, whorls equally convex on both sides, round and promi- 
 nent, the outer one not keeled. 
 
 Planorbis las vis, Gray, Sfc. 
 
 This little shell somewhat resembles the foregoing, 
 but may be readily distinguished by being smaller, 
 about one-fifth of an inch in diameter, and having the 
 whorls much closer set, and more rounded, especially 
 on the upper disk. It is also destitute of the spiral 
 stria3 or hairs. 
 
 Hob. Though generally distributed it is somewhat 
 local. It is found in similar habitats to the preceding. 
 It occurs in Cornwall and the south of Wales, Ox- 
 fordshire and the adjacent counties, Staffordshire and 
 Somersetshire, North Stainley, near Ripon, and at 
 Ackworth, near Pontefract, in an old depopulated fish- 
 pond, on Potomogeton crispus. It has also been met 
 with in other places in Yorkshire, Durham, and North- 
 umberland. 
 
 P. NAUTILEUS. Linnceus. PI. VII, fig. 23. 
 
 Shell minute, with numerous transverse ridges ; whorls depressed 
 and keeled ; aperture oval. 
 
 Planorbis imbricatus, Mull., tyc. 
 
 A beautiful little shell, and may be readily distin- 
 guished by the spinous ridges on the outer whorl. 
 From an eighth to a tenth of an inch in diameter. The 
 shell is of an olivaceous horn colour, often covered 
 with a darker epidermis, not polished. Whorls from 
 three to three and a half, which are well defined. 
 Animal pale grey. 
 
 Hob. Somewhat local, though generally diffused, 
 and in some places abundant. It prefers stagnant 
 water in ponds, ditches, &c., generally adhering to 
 aquatic plants, often in colonies. Ponds near Ack- 
 worth, in profusion, ditches near Middlesbro', &c. It 
 occurs in most parts of Ireland. 
 
 P. CARINATUS. Mutter. PI. VII, fig. 24. 
 
 Shell horn coloured, somewhat transparent and polished, nearly 
 smooth, strongly Cflrinated. 
 
62 
 
 The shell of this species is of an ashy horn colour, 
 often covered with an outer brown epidermis, rather 
 shining and nearly smooth. It is about half-aii-inch 
 in diameter with five deeply-divided whorls, which 
 gradually incline to the outer edge, which is more or 
 less keeled. Upper disk rather concave, lower disk 
 flat. 
 
 var. DISCIFORMIS, has the lower disk almost convex, 
 and the keel more central. 
 
 Hob. Stagnant or slowly-running waters in almost 
 every district, but it is local. More common in the 
 south than the north. Very fine at Norton, near 
 Stockton. 
 
 P. MARGINATUS. Drapcirnaud. PI. VII, fig. 8. 
 
 Shell brown colour, slightly concave above, flat beneath, striolate, 
 not polished, carinated. 
 
 Helix planorbis, Linn. 
 
 This species very much resembles the last, but may 
 be distinguished from it by being thicker and having 
 the whorls more rounded, the outer one being more or 
 less carinated near the base, the upper part of which is 
 rounded, .not shelving. The mouth is rhombic, but 
 rounded in front. It is covered with an olivaceous 
 black, or ferruginous coating, which is not polished, and 
 distinctly wrinkled. About half-aii-inch in diameter. 
 
 The shells included under this species vary much 
 both in shape and colour ; the keel, which in some 
 specimens is prominent, is scarcely discernible or alto- 
 gether wanting in others. It has, by some naturalists, 
 been divided into several distinct species. 
 
 var. RHOMBEUS, shell higher than usual, with the 
 gyrations rather more compact, more convex above and 
 concave below ; keel almost obsolete. 
 
 var. DRAPARNALDI, somewhat smaller than the 
 above, and resembles a young carinatus. 
 
 Hob. This is by far the commonest of the Planorbes, 
 
PLANORBIS. Dd 
 
 being found abundantly in a number of localities in 
 almost every district, in ponds or ditches of stagnant 
 water, or slowly-running streams and rivers. 
 
 P. VORTEX. Linnceus. PL VII, fig. 30. 
 
 Shell depressed, thin, nearly flat above, concave beneath ; whorls 
 six or seven, convex above, flat beneath ; circumference somewhat 
 carinated. 
 
 Helix vortex, Linn. 
 
 Shell extremely depressed, discoid, about three 
 eighths of an inch in diameter, thin, transparent, and 
 closely wrinkled, of an olivaceous horn colour. The 
 body is broader above than below. Aperture a little 
 angular, broader than long. Volutions slightly con- 
 cave above, flat underneath, which forms a sharp keel 
 at the base of the periphery. The animal varies in 
 colour, but is generally grey, with darker head. Ten- 
 tacles long. 
 
 Hob. Widely distributed and common in most dis- 
 tricts, in ponds, ditches, and canals, preferring those 
 which flow slowly or are quite stagnant. 
 
 P. SPIRORBIS. Linnceus. PL VII, fig. 29. 
 
 Shell thin, depressed, concave both above and below ; mouth 
 roundish. 
 
 Helix spirobis, Mont., c. 
 
 Very closely resembling the last species, but may be 
 distinguished by having both disks concave ; it is also 
 less, but rather thicker. The body consists of five or 
 six whorls, the outer one of which is not much carinated. 
 
 Hal. Very much the same localities and situations 
 as the former ; they are very often found in the same 
 pond, though seldom so plentifully. 
 
 P. CONTORTUS. Linnceus. PL VII, fig. 31. 
 
 Shell nearly flat above, deeply umbilicate beneath ; whorls closely 
 coiled but separated by a deep surture ; aperture narrow and crescent- 
 shaped. 
 
 Helix contorta, Linn., fyc. 
 
64 LIMNJEADJE. 
 
 This pretty little shell cannot possibly be confounded 
 with any of the other species of Planorbis. Its whorls 
 are six in number, and extremely narrow, but promi- 
 nent and well defined. Diameter about one-fifth of an 
 inch, height one tenth. The mouth is peculiarly small 
 and unarmed. Aperture of a narrow crescent shape, 
 only slightly produced on the upper side. 
 
 Hob. Widely distributed throughout the British 
 Isles, though absent in some districts. It may generally 
 be found in ponds, ditches, or slow streams. 
 
 P. NITIDUS. Mutter. PI. VII, fig. 22. 
 
 Shell depressed, smooth, polished, transparent, horn coloured, cari- 
 nated at the periphery, flat above, concave beneath, wrinkled. 
 
 Helix fontana, Light. Planorbis complanatus, Drap. 
 
 This shell, which is by no means common, closely 
 resembles the succeeding species, but is more depresed, 
 less polished, pale coloured, and devoid of septa. 
 Whorls more convex and distinct and rather wrinkled ; 
 umbilicus much larger. The shell is seldom a quarter 
 of an inch in diameter. 
 
 Hob. Though this species is not mentioned in the 
 fauna of several districts, there is reason to believe it is 
 generally distributed through England. We have met 
 with it, but sparingly, in several localities in Yorkshire, 
 in clear stagnant water on acquatic plants. 
 
 P. LACUSTRIS. Lightfoot. PI. VII, fig. 25. 
 
 Shell highly polished, with internal partitions ; whorls flattened ; 
 periphery carinated ; aperture triangular. 
 
 Planorbis nitidus, Mull. Sementina lineata, Flem., 
 Gray. 
 
 This beautiful Planorlis is about a quarter of an 
 inch in diameter, and remarkably smooth, shining, and 
 transparent, of an olivaceous brown colour, with white 
 radiations on the outer volution, exhibiting the internal 
 partitions. The upper side is flattened convex, having 
 the middle whorls of the spire thick ; the under side 
 
LIMNjEUS. 65 
 
 flat, with a very small deep umbilicus. Body whorl 
 extremely large filling nearly the whole surface, the 
 circumference of which slopes gradually and rather 
 convexly to an angulated edge, which is below the 
 centre of the shell. 
 
 Hob. Somewhat common in the south of England, 
 but becomes more rare towards the north. Its north- 
 ernmost English locality is near York. It is recorded 
 as occurring in the south of Scotland. Ditches and 
 ponds of stagnant water, containing aquatic plants, 
 are its favourite resorts. 
 
 LIMNJEUS. Draparnaud. 
 
 Shell Ovate, dextral, diaphanous ; aperture ovate, bounded 
 
 by an entire margin, without operculum. 
 Animal With a broad head and compressed tentacles, with 
 
 eyes at their inner bases ; mantle simple, 
 
 L. PEREGER. Muller. PI. VII, fig. 41. 
 
 Shell striolate, more or less ventricose ; spire short, rather acute ; 
 whorls convex. 
 
 Helix putris, Penn. Limnseus ovatus, Drap. Lim- 
 na3us vulgaris, Pfeif., Sfc. 
 
 This commonest of our fluviatile mollusks, is of an 
 infinite variety of forms and shapes ; two or three of 
 the principal of which we will endeavour to describe. 
 The shell of the normal form is of a greyish or yellowish 
 colour, thin, not fragile, glossy, concentrically striated ; 
 slightly wrinkled longitudinally ; spire more or less 
 depressed, consisting of four whorls. Mouth large, 
 oval, oblong, but peaked above ; umbilicus small, 
 sometimes nearly obsolete. 
 
 var. OVATA. Ventricose, with an acute but ex- 
 ceedingly short spire. Body whorl much expanded, 
 forming a capacious mouth. 
 
 var. LINEATA, body large, spire not long, with the 
 apex often corroded ; generally of an olivaceous ferru- 
 ginous colour, the outer whorl lineated. 
 
 var. MARGINATA, Michaud, has the internal lip of 
 the outer rim thickened. 
 
66 
 
 We have noticed a small variety, acuta, with the 
 spire elongated and acute, and the suture more dis- 
 tinct and more oblique ; about half an inch in length. 
 
 Hob. Common every where, and in all kinds of 
 localities, though it seems to prefer ponds and ditches 
 of stagnant water. 
 
 L. AURICULARIUS. LinncBus. PL VII, fig. 45. 
 
 Shell very much inflated, almost as broad as long ; spire short and 
 acute ; aperture an oblique circular oval, vastly expanded ; outer lip 
 patulous. 
 
 Helix auricularia, Linn., fyc. 
 
 This elegant shell may be distinguished from the 
 varieties of pereger, which bear a close resemblance in 
 many respects, by the exceedingly small acute spire, and 
 capacious mouth, which occupies about two-thirds of 
 the area. Is is of a shining horn colour, coarsely 
 wrinkled, and more or less longitudinally striated ; the 
 outer lip is expanded and reflexed, forming a slight 
 umbilical hollow behind. Length an inch, breadth 
 three quarters of an inch. 
 
 var. ACUTUS, has the mouth less capacious and the 
 body much smaller ; spire very similar. 
 
 Animal of an olivaceous yellowish grey, with spots. 
 
 Hdb. This shell is found chiefly in the southern and 
 midland counties, and may be considered somewhat 
 local, as it is wanting in many districts. Abundant in 
 many places round London. The recorded localities 
 are Clumber Lakes, Notts, York, Hemsworth dam 
 near Ackworth, &c. It prefers still waters. 
 
 L. BURNETTI. Alder. PL VII, fig. 40. 
 
 Wrinkled, mouth very ample, folds indistinct ; spire depressed, 
 almost level. 
 
 Gulnaria lacustris, Leach. 
 
 This shell was first detected by Burnett, of New- 
 castle, in the stomach of trout caught in Lock Shene, 
 Dumfriesshire, where it was taken alive. It is closely 
 allied to some of the many varieties of L. pereger. The 
 
LIMN^US. 
 
 body whorl is large and broadly tumid in the middle, 
 displaying a capacious sub-pyriform mouth. Length 
 two-thirds of an inch, breadth one-half. 
 
 var. LACUSTRIS. Forbes and Hanley remark, (Hist. 
 B. M., vol. IV, p. 175,) "With some hesitation we 
 annex as a variety of this species, Limnceuspereger, var. 
 4, (lacustrisj of Gray's Manual. The apex is eroded, 
 not quite sunken, and yet barely elevated above the 
 body whorl, the pillar is much appressed. It is not 
 improbable that this and the typical Burnetti may 
 prove in the end to be the abnormal forms of pereger" 
 
 Hob. Deep water, lakes, &c. 
 
 L. STAGNALIS. LinncBUs. PL VII, fig. 34. 
 
 Shell conic, ovate ; spire long, beautifully turreted and acute ; 
 whorls six or seven, the lower ones much inflated, displaying a capa- 
 cious pyriform mouth. 
 
 Helix stagnalis, Linn.,, fyc. 
 
 This most elegant Limnceus is often an inch and a 
 half in length, and an inch in breadth ; the shell is of 
 a greyish white colour ; the spire produced and conical, 
 consisting of six whorls which are convex and turned , 
 at times subangulated, separated by an oblique profound 
 suture. The mouth is usually pyriform. Outer lip 
 large in full grown specimens, and flattened in the 
 middle. This shell varies much in size and thickness. 
 It almost always presents a more or less lunated ap- 
 pearance. 
 
 var. FRAGILIS, much smaller and thinner, the body 
 not so large and more regularly convex ; spire longer 
 in proportion, the whorls of which are more regularly 
 convex and depressed, not lineated. It somewhat 
 resembles the young of stagnalis, but is found separate 
 and distinct. Animal olivaceous yellow, paler beneath. 
 
 Hob. Common in most parts of England, except 
 the south west and some of the mountainous districts ; 
 the variety is somewhat more local and gregarious in 
 its habits. We have found them abundantly in the 
 south of Durham, and north of Yorkshire. Stagnant 
 and slow waters. 
 
 r 2 
 
68 
 
 L. TRUNCATULTJS. Muller. PI. VII, fig. 35. 
 
 Shell elongated, conic oval, perforated ; spire long and consisting of 
 six deeply divided volutions. 
 
 Helix fossaria, Mont. Limneus minutus, Pfeif., fyc. 
 
 The smallest of the Limncei, seldom attaining half- 
 an-inch in length and three lines in breadth, of a pale 
 horn colour, smooth and glossy. In shape it resembles 
 palustris, but is much smaller and has the volutions 
 rounder and more deeply and abruptly divided. They 
 are extremely variable in size, according to the locality 
 in which they are found. Animal of a light or dusky 
 grey. 
 
 Hob. On the margin of muddy streams, in marshy 
 places, &c., often covering itself with a coating of mud, 
 probably for the twofold purpose of retaining the 
 moisture and protecting it from observation. Generally 
 diffused throughout the British Isles, and common in 
 many places. 
 
 L. GLABER. Mutter. PL VII, fig. 36. 
 
 Shell elongated, cylindrical, tapering ; whorls rounded ; aperture 
 elongate, ovate, small. 
 
 Helix octanfracta, Mont. Limneus elongatus, Drap. 
 
 Shell longer than truncatulus and more gradually 
 tapering, thin, glossy, and horn coloured, but often 
 covered with a dark epidermis. Whorls seven or eight 
 in number, and varying much in convexity ; suture 
 profuiid, slanting ; body whorl not quite so long as the 
 spire. About three quarters of an inch in length, by 
 one quarter in breadth, but varies much in size. Ani- 
 mal blackish or dusky. 
 
 Hob. This shell is widely diffused, but rather 
 local, and by no means abundant ; it inhabits ponds or 
 ditches of stagnant water, in Wilts, Somersetshire, 
 Staffordshire, near Pontefract, York, and many 
 parts of Yorkshire, Durham, and Northumberland ; 
 probably more common in the north than the south of 
 England. 
 
LIMN^EUS. 69 
 
 L. PALUSTRIS. Linnaeus. PL VII, fig. 39. 
 
 Shell ovate, oblong, spire tapering, of a purplish raw-umber colour ; 
 aperture ovate about the same length as the spire. 
 
 Helix palustris, GmeL, fyc. 
 
 This shell varies very much in size, shape, and 
 colour, but cannot well be confused with any other 
 species. It is generally an inch or more long and half- 
 an-inch broad. Whorls seven, hardly raised, but 
 divided by a distinct oblique suture. Aperture about 
 half as long as the shell, of a chocolate colour inside ; 
 outer lip regularly arched. Animal dusky grey, tinged 
 with olive. 
 
 Hob. Stagnant waters, with muddy bottoms, in 
 most parts of the British Isles, and found more abun- 
 dantly than the three preceding. 
 
 L. GLTJTINOSUS. Muller. PL VII, fig. 32. 
 
 Shell subglobose, thin and transparent, finely wrinkled ; of a pale 
 amber colour, spire very small ; aperture large. 
 
 Helix glutinosa, Mont. Amphipeplea glutinosa, 
 Gray. 
 
 The shell of this species is extremely thin and 
 highly polished. The spire is much depressed, con- 
 sisting of three whorls ending obtusely ; the body 
 whorl is remarkably large, forming a capacious mouth, 
 extending almost the whole length of the shell, which 
 is ovate but acute above. About half-an-inch in length 
 and three eighths in breadth. Animal large, of a pale 
 dull yellow colour, with brighter spots ; mantle lobes 
 dilated ; tentacles broad and flat. 
 
 Hob. This shell is rare, though at times rather 
 plentiful where it occurs. The south eastern counties, 
 the Cherwell, Oxfordshire, Lake Windermere, &c., are 
 recorded localities. It seems to prefer deep and still 
 waters. 
 
 L. INVOLUTUS. Harvey. PI. VII, fig. 33. 
 
 Shell ovate, thin, transparent ; spire flat, consisting of three or four 
 volutions ; aperture large, pear shaped. 
 
70 LIMNJEAD-3E. 
 
 Amphipeplea involuta, Gray. 
 
 This rare Limnceus has only been discovered in one 
 locality. It is thus described by the late W. Thomp- 
 son, " Shell polished, extremely thin, of a pale amber 
 colour, with coarse longitudinal strise. It approaches 
 L. glutinosus more nearly than any other species. The 
 aperture is very large, wide at the base and extending 
 to the apex ; margin reflected only when it joins the 
 pillar." About five lines in length and three and a 
 half in breadth. 
 
 Hob. A small Alpine lake, at Cromaglaun moun- 
 tain, near Killarney. 
 
 ANCYLUS. Geoffroy. 
 
 Shell Limpet shaped, conical ovate, simple and recurved ; 
 aperture ample, interrupted ; apex on the left side by a 
 semi-lunar scar ; no operculum. 
 
 Animal Conical, filling the whole of the shell, head broad, 
 tentacles triangular ; mantle simple, not reflected. 
 
 A. FLUVIATILIS. Mutter. PL VIT, fig. 37. 
 
 Shell conoid ; the apex recurved and near one end, bent to the right ; 
 aperture oval. 
 
 Patella lacustris, Linn. 
 
 The fresh water limpets, for so these shells are de- 
 nominated, are very much like the marine Patellce, and 
 were for a long time placed by naturalists under that 
 genus. The shell of flumatilis is about a quarter of an 
 inch in length, two lines and a half in breadth, and 
 almost as high as long. It is semi-transparent, but 
 covered with an olivaceous or black epidermis, slightly 
 striated. The inside of the shell bluish white and 
 glossy. Animal light grey. 
 
 Hob. Abundant on stones, in clear brooks or run- 
 ning streams, in all parts of the British Isles. 
 
 A. OBLONGUS. Light foot. PL VII,' fig. 38. 
 
 Shell elongated, oblong, compressed ; apex in the middle and very 
 slightly recurved, bent to the left ; aperture oblong. 
 
AXCYLUS. 71 
 
 Ancylus lacustris, Mutt. Patella oblonga, Light. 
 Velletia lacustris, Gray. 
 
 This little mollusk may be readily distinguished from 
 the former species by being more elongated and de- 
 pressed ; having the apex less recurved,, and to the left 
 instead of the right ; it is also thinner and more trans- 
 parent. The apex is placed near the centre of the 
 shell. Length a quarter of an inch ; breadth the ninth 
 of an inch. Animal dark grey, dextral, similar to flum- 
 atilis, except in the dentition. 
 
 Hal. Generally distributed in England, but some- 
 what local, it prefers stagnant ponds, and is generally 
 found adhering to grass and aquatic plants. 
 
 AURICULIDJE. 
 
 CONOVOLUS. Lamark. 
 
 Shell Spiral, oval ; aperture ovate, pyriform, entire, toothed 
 within ; outer lip simple or slightly reflected, more or 
 less thickened. JN~o operculum. 
 
 Animal With two triangular and ringed tentacles, having 
 eyes at their inner bases. 
 
 C. BIDENTATUS. Montagu. PI. VII, fig. 43. 
 Shell ovate, ventricose, smooth ; pillar with two folds. 
 Voluta bidentata, Mont. 
 
 The shells belonging to this species vary in shape, 
 but are uniformly of a yellowish horn colour above and 
 white underneath the petiostraca. Whorls six or seven, 
 small and moderately convex. It has two teeth or folds 
 on the inner lip, as the name implies, which readily 
 distinguish it from any other of the genus. The spire 
 of the shell is sometimes eroded. Not quite a quarter 
 of an inch in length, breadth a line and a half. 
 
 var. ALBUS, (PI. VII. fig. 44,) narrower, slenderer, 
 and more fragile ; spire more produced. 
 
 Animal white, with two very flat, short, setose tenta- 
 cula?, with eyes at their inner bases. 
 
1% AUHICUL1DJE. 
 
 Hob. The conovuli inhabit brackish water near the 
 sea, in crevices of rocks near high water mark. The 
 recorded localities are Devon and Cornwall, and other 
 places on the south-west coast, Isle of Man, near Mid- 
 dlesbro', &c. 
 
 C. DENTICTJLATUS. Montagu. PL VII, fig. 42. 
 
 Shell oblong, smooth, coloured, spire conical ; aperture pyriform, 
 protected by more than two teeth. 
 
 Voluta denticulata, Mont. 
 
 The individuals included under this species vary 
 much in size, in colour, and in the length of the spire 
 and convexity of the whorls. The mouth contains 
 three or six teeth, which are sometimes distinct, at 
 others nearly obsolete, they are placed on both sides 
 the aperture. It differs from bidentatus in the colour 
 of the shell, (which is a purplish brown above a yel- 
 lowish horn coloured periostraca,) and in the position 
 of the teeth. Length about a third of an inch, breadth 
 two lines. The variety myosotis is similar except in 
 the aperture, but for the most part stronger and of a 
 deeper tint of colouring. Inner lip with only two or 
 three teeth, outer lip with one. Animal yellowish 
 or bluish white, tentacles filiform and compressed, with 
 eyes at their inner bases. 
 
 Hob. Brackish water in the neighbourhood of the 
 sea. More common in the south than in the north of 
 England. We have however met with it at Middles- 
 bro'. The variety occurs in the Thames and Avon, 
 near Bristol, as well as other places. 
 
 CARYCHITJM. Mutter. 
 
 Shell Spiral, thin, cylindrical, aperture small, oblong, 
 toothed; peristome thickened; no operculum. 
 
 Animal With an elongated ringed muzzle, two cylindrical 
 obtuse tentacles, with eyes at their inner bases. 
 
 C. MINIMUM. Mutter. PI. VII, fig. 46. 
 Turbo carychium, Gruel. Auricula minima, Drap.. 
 
 SfC. 
 
CARYCH1UM. 73 
 
 This smallest of British shells may be readily distin- 
 guished by its pretty little white or cream coloured, 
 tapering, cylindrical, and spiral shell, which is a line 
 in length and half a line in breadth. Whorls five or 
 six in number, moderately rounded, end tapering to a 
 blunt apex ; peristome broadly reflected. The aper- 
 ture suboval, provided with three or four teeth, one on 
 the outer lip, two on the inner, and one on the pillar 
 lip. 
 
 var. SUBEDENTTJLUM, with the teeth almost obsolete. 
 Animal creamy white with large eyes. 
 
 Hob. Generally diffused over the British Isles. It 
 may be found by carefully looking amongst moss, 
 grass, &c., in damp situations. 
 
 CYCLOSTOMID^E. 
 
 CYCLOSTOMA. Montfort. 
 
 Shell Ovate, spiral, turreted, mouth simple, oval ; with an 
 operculum consisting of four or five oval depressed 
 whorls, terminating in an ecccentric nucleus. 
 
 Animal With a proboscidiform muzzle ; two subulate tenta- 
 cles, with eyes at their external bases. 
 
 C. ELEGANS. Mutter. PI. VII, fig. 48. 
 
 This is the only British representative of this inter- 
 esting genus of mollusks. It may be readily distin- 
 guished by its thick strong shell, which is covered by 
 a purplish brown periostraca which is marked with 
 numerous, close-set, raised, longitudinal striae. Whorls 
 five, simply rounded ; sutures profound and rather 
 oblique ; spire turreted, and terminating in a blunt 
 apex, much sculptured; mouth circular, inside of a 
 reddish colour. The shell is dextral ; length half an 
 inch, breadth one third of an inch. 
 
 The variety marmorea of Brown, is much smaller 
 and more finely striated. 
 
 Animal of a dark brown colour, with an elongated 
 head and subulated tentacles. 
 
74 CYCLOSTOMID^E. 
 
 Hal. Hedges, under stones, &c., in chalk and lime- 
 stone districts. It occurs at Hemsley, Thorpe, Hackfall 
 near Ripon, and other places in Yorkshire, near Ken- 
 dal, and most parts of the south of England. 
 
 ACME. Hartman. 
 
 Shell Cylindrical, spiral, turreted, obtuse at the apex ; ap- 
 erture ovate, entirely toothless ; operculum very thin and 
 corneous. 
 
 Animal With two long and slender tentacles, with eyes 
 at their inner bases. 
 
 A. LINEATA. Draparnaud. PL VII, fig. 47. 
 
 This delicate little gem, which is by no means com- 
 mon, may be readily distinguished from C. minimum, 
 which it nearly resembles in size, by being more 
 cylindrical and having a blunter apex, and being of a 
 brownish or rufous colour. Whorls six, slightly 
 raised but well defined. Mouth small and circular. 
 Length of the shell about one-tenth of an inch, and 
 about half that in breadth. Animal much the same 
 colour as the shell. 
 
 Hob. Rare and local in England and Ireland, not 
 found in Scotland. It has been found in Northum- 
 berland ; Airyholme Wood, Hemsley, and Ripon, in 
 Yorkshire ; Oxfordshire ; and one or two other places. 
 It prefers very damp situations, at the roots of moss and 
 Hepatica, in woods containing peaty soil. 
 
GLOSSARY OF CONCHOLOGTCAL TERMS. 
 
 Anterior. In bivalves is the side on which the head, or 
 
 part analagous to the head of the animal lies. 
 Aperture or Mouth. The entrance to the spiral cavity of 
 
 univalve shells. 
 Apex. The top or nucleus of the shell, from which point 
 
 the shell, enlarging as it descends, takes a spiral, 
 
 arched, straight, oblique, or irregular course. 
 Axis. The imaginary line, round which the whorls of a 
 
 spiral shell revolve. 
 
 Bivalve. A shell composed of two separate pieces. 
 Body Whorl. The last whorl, constituting the bulk of the 
 
 shell. 
 Byssus. The fibres by which some bivalve shells adhere to 
 
 stones, &c., under the water. 
 Cardinal Teeth. The teeth upon the hinge directly beneath 
 
 the umbones of a bivalve shell, as distinguished from the 
 
 lateral teeth, which are placed at a distance on each 
 
 side. 
 
 Garinated. Applied to any shell having a raised, thin edge. 
 Cinereous. Ash-coloured. 
 Clausium. A ligamentous membrane attached to the animal 
 
 of Clausilia. (See genus Clausilia, p. 52.) 
 Clavate. When one extremity of the shell is attenuated, 
 
 and the other becomes suddenly rounded. 
 Columella. A solid column found by the inner sides of the 
 
 volutions of spiral univalves. 
 Columella lip. The inner lip. 
 Concentric. A term applied to the direction taken by the 
 
 lines of growth in spiral and other shells, (longitudinal 
 
 of some authors). 
 Corneous. Horny. 
 Corroded. When the umbones, apices, and other parts of 
 
 shells are worn away by water. 
 
76 GLOSSARY. 
 
 Orenated. Applied to small notches not sufficiently defined 
 
 to be called teeth. 
 
 Decussate. Intersected by striae crossing each other. 
 Denticulated. Having little teeth or raised points. 
 Dextral. Place the point of a spiral shell towards the eye 
 
 with the mouth downwards ; if the aperture be on the 
 
 right side of the axis, it is a dextral shell, if otherwise, 
 
 it is sinistral or reversed. 
 
 Discoidal. "When the whorls form a flattened spire. 
 Dorsal. A dorsal shell is one placed upon the back of the 
 
 animal. The dorsal margin of a bivalve shell is that 
 
 on which the hinge is placed ; the opposite is called 
 
 ventral. 
 Epidermis. The fibrous, horny, external coating of shells. 
 
 The outer covering of extraneous matter with which 
 
 some shells are generally coated. 
 Epipnragm. The membranous or calcareous substance 
 
 with which some mollusks close the aperture, when 
 
 they retire to hibernate. 
 Equivalve. A term applied to a bivalve shell when the 
 
 valves are equal to each other in dimensions. 
 External. A shell which contains the animal, and is not 
 
 covered by the mantle. 
 
 Granulated. Covered with minute rough grains. 
 Hinge. The edge of the bivalve shells near the umbones, 
 
 including the teeth and ligament. 
 Inequilateral. A term applied to a bivalve shell when its 
 
 extent on one side of the umbones is greater than that 
 
 on the other. 
 Inequivalve. The two principal valves differing from each 
 
 other in diameter or convexity. 
 Inflected or Inflexed. Turned inwards. Applied to the lip 
 
 of a spiral shell when turned towards the body whorl. 
 Inner lip. That edge of the aperture of a univalve shell, 
 
 which is near to the imaginary axis, as distinguished 
 
 from the outer lip, or that which is on the outer side. 
 Internal ligament. The ligament of a bivalve shell which is 
 
 placed within the closed part of the hinge, so as not to 
 
 be seen when the valve is shut. 
 
 Keel. A flattened ridge, resembling the keel of a ship. 
 Lamellated. Having the layers of which the shell is com- 
 posed overlaying each other. 
 
GLOSSARY. 77 
 
 Lateral. The lateral teeth take their rise near the umbones, 
 and proceed towards the sides of the shell. 
 
 Ligament. The external substance by which the two valves 
 of bivalve shells are connected. 
 
 Lip. The inner lip, or labium, is used to express that side 
 of the aperture nearest to the axis ; the outer lip, or 
 labrum, is the edge of the aperture at the greatest dis- 
 tance from the axis. 
 
 Longitudinal. Lengthwise. Longitudinal striae, &c. 
 
 Mantle. The cutaneous and fleshy envelope which invests 
 the interior of the shell of conchifera ; in Limaces the 
 external fleshy substance covering the shell, sometimes 
 called the shield. 
 
 Marginated. Having an edge or border thicker than the 
 rest. 
 
 Nucleus. A kernel. Anything forming a centre round 
 which matter is gathered. The nucleus of a shell is 
 the first part formed ; generally applied to the apex of 
 spiral shells. 
 
 Oblique. In a slanting direction. The whorls of spiral 
 univalves generally take an oblique direction, in refer- 
 ence to the imaginary axis of the shell. 
 
 Obsolete. Used to express an indistinctness of character. 
 
 Obtuse. Blunt ; generally used to express the character ol 
 the spire. 
 
 Operculum. The plate which serves to protect the aperture 
 in some mollusks. 
 
 Patelliform. Shaped like a disk. 
 
 Pedicle or Peduncle. The stem or organ of attachment of 
 some water-shells 
 
 Pellucid. Clear and somewhat transparent. 
 
 Periostraca. The natural epidermis or thin skin which 
 covers some shells. 
 
 Peristome. The lip or rim that surrounds the aperture of 
 most univalves. 
 
 Pillar. The name of the column which forms the axis of 
 spiral shells, round which the whole revolves. 
 
 Plait or Fold. A term generally applied to the promi- 
 nences on the inner lip of some univalve shells. 
 
 Posterior. The posterior, or hinder part of a bivalve shell, 
 is that in which the siphonal tube of the animal is 
 placed. 
 
78 GLOSSARY. 
 
 Pyriform. Shaped like a pear, that is large and rounding 
 
 at one end and gradually tapering a,t the other. 
 Radiating. A term applied to the ribs, striae, bands of 
 
 colour, &c.j when they meet in a point at the umbones 
 
 of a bivalve shell. 
 
 Reflected or reflexed. Turned or folded backwards. 
 Reversed or Sinistral. See Dextral. 
 Septa. The internal laminar division between the whorls of 
 
 most univalve shells. 
 
 Simple. Single, entire, uninterrupted, undivided. 
 Sinistral. On the left side, reversed. 
 Spines. Thin pointed spikes. 
 Spiral. Revolving from a centre. 
 Spire. The cone or pyramid of some univalve shells. The 
 
 spire, in descriptions, includes all the whorls above the 
 
 mouth of the shell. 
 
 Striae, striulce. Small channels in shells. 
 Sulcated. Having grooves or furrows. 
 
 Suture. A seam, stitch, or joining together; applied par- 
 ticularly to the line which marks the joining of the 
 
 whorls of the spire. 
 Tentacle. A filiform process round the mouth of various 
 
 mollusks, being either an organ of feeling, prehension, 
 
 or motion. 
 
 Transverse. Crosswise. 
 Turreted. "When the whorls of univalve shells rise regularly 
 
 above each other, so as to have the appearance of little 
 
 turrets. 
 Umbilicus. The hollow in a spiral shell, occasioned by its 
 
 whorls or convolutions not touching each other. 
 Umbones. The points in bivalve shells which constitute the 
 
 nucleus or apex of each valve, and are generally situated 
 
 near the hinge. 
 
 Univalve, consisting of only one shell or valve. 
 Ventral. The margin of a bivalve shell, opposite the hinge. 
 Ventricose. Bounded out. 
 Whorl or Volution. A wreath, convolution, or turn of the 
 
 spire of a univalve shell. 
 
INDEX. 
 
 PLATE 1. 
 Pig. Page. 
 
 1 Unio margaritiferus ... 13 
 
 2 Cyclas rivicola 7 
 
 3 Cyclas cornea 8 
 
 4 Cyclas caliculata 8 
 
 5 Cyclas lacustris 8 
 
 6 Pisidium obtusale 9 
 
 7 Pisidium pusillum 9 
 
 8 Pisidium cinereum 10 
 
 9 Pisidium nitidum ...... 10 
 
 10 Pisidium pulchellum ... 11 
 
 11 PisidiumHenslowianum 11 
 
 1 2 Pisidinm amnicum 12 
 
 PLATE II. 
 1 Anodonta cygnea ...14, 15 
 
 PLATE III. 
 
 1 Unio pictorum 13 
 
 2 Unio tumidus 12 
 
 3-4 Dreissena polymorpha . . 16 
 
 PLATE IV. 
 
 1 Neretina fluviatilis 16 
 
 2 Assiminia Grayana 19 
 
 3 Valvata cristata 19 
 
 4 Valvata piscinalis 19 
 
 5 Paludina Listeri 17 
 
 6 Paludina vivipera 17 
 
 7 Bithinia tentaculata ... 18 
 
 8 Bithinia Leachii 18 
 
 9 Limax agrestis 21 
 
 10 Limax Sowerbii 24 
 
 11 Limax gagates 24 
 
 1 2 Limax cinereus 22 
 
 13 Limax tenellus 23 
 
 14 Limax arborum 22 
 
 PLATE V. 
 
 1 Avion empiricorum 20 
 
 2 Limax brunneus 23 
 
 Fig. Page. 
 
 3 Anon hortensis 21 
 
 4 Limax flavus 23 
 
 5 Testacella haliotoidea... 24 
 
 6 Geomalacus maculosus. 21 
 
 7 Arion flavus 20 
 
 8 Zonites cellarius 26 
 
 9 Zonites nitidulus 27 
 
 1 Zonites radiatulu s 28 
 
 1 1 Zonites cry tallinus 30 
 
 12 Vitrina pellucida 25 
 
 13 Zonites alliarius 26 
 
 14 Zonites purus 27 
 
 15 Zonites nitidus 28 
 
 16 Zonites excavatus 29 
 
 17 Helix pomatia 31 
 
 PLATE VI. 
 
 1 Helix aperta 30 
 
 2 Helix aspersa 31 
 
 3 Helix nemoralis 33 
 
 4 Helixhybrida 34 
 
 5 Helix arbustorum 32 
 
 6 Helix hortensis 33 
 
 7 Helix hispida 38 
 
 8 Helix pisana 34 
 
 9 Helix Cantiana 32 
 
 10 Helix virgata 34 
 
 11 Helix sericea 39 
 
 12 Helix Carthusiana 33 
 
 13 Helix lamellata 39 
 
 14 Helix fulva 40 
 
 15 Helix caperata 35 
 
 16 Helix lapicida 36 
 
 17 Helix aculeata 40 
 
 18 Helix ericetorum 35 
 
 19 Helix rufescens 37 
 
 20 Halix pulchella 41 
 
 21 Helix obvoluta 36 
 
 22 Helix revelata 38 
 
 23 Helix rotundata 41 
 
 24 Helix fusca .. ..40 
 
80 
 
 INDEX. 
 
 Fig. Page. 
 
 25 Helix umbilicata 42 
 
 26 Helix limbata 43 
 
 27 Clausilia laminata 52 
 
 28 Clausilia biplicata 53 
 
 29 Clausilia plicatula 53 
 
 30 Clausilia nigricans 54 
 
 31 Clausilia nigricans var 
 
 dubia 54 
 
 32 Zualubrica 54 
 
 33 Azeca tridens 55 
 
 34 Helix pygmsea 43 
 
 PLATE VII. 
 
 1 Bulimus acutus 43 
 
 2 Bulimus. Lackharaensis 44 
 
 3 Bulimus obscurus 44 
 
 4 Pupa umbilicata 45 
 
 5 Pupa muscorum 46 
 
 6 PupaAnglica 46 
 
 7 Pupa secale 47 
 
 8 Pupa edentula 47 
 
 9, Pupa minutissima 48 
 
 10 Pupa pygmsea 48 
 
 11 Pupa substriata 49 
 
 1 2 Pupa anti vertigo 49 
 
 13 Pupapusilla 50 
 
 14 Pupa Venetzii 50 
 
 15 Balsea fragilis 51 
 
 16 Achatina acicula 56 
 
 17 Planorbis corneus 59 
 
 18 Succinea putris 57 
 
 19 Succinea oblonga 58 
 
 2 Phy sa fontinalis 58 
 
 2 1 Planorbis glaber 61 
 
 22 Planorbis nitidus 64 
 
 23 Planorbis nautileus 61 
 
 24 Planorbis carinatus 61 
 
 25 Planorbis lacustris 64 
 
 . 60 
 
 Planorbis marginatus... 62 
 Planorbis spirorbis ... 
 
 Planorbis vortex 
 
 Planorbis contortus... 
 
 Limnseus glutinosus 
 Limnseus involutu s . . . 
 
 Fig. 
 
 26 Physa hypnorum . 
 
 27 Planorbis albus . 
 28 
 
 29 
 30 
 31 
 32 
 33 
 34 
 35 
 36 
 37 
 38 
 39 
 40 
 41 
 42 
 43 
 44 
 
 Limnseus stagnalis ... 
 Limnseus truncatulus 
 
 Limnseus glaber 
 
 Ancylus. fluviatilis ... 
 Ancylus oblongus ... 
 Limnseus palustris ... 
 Limnseus Burnetti ... 
 Limnseus pereger ... 
 Conovulus denticulatus. 72 
 Conovulus bidentatus ... 71 
 Conovulus bidentatus 
 var albus 71 
 
 45 Limnaeus auricularius... 66 
 
 46 Carychium minimun ... 72 
 
 47 Acme lineata 74 
 
 48 Cyclostoma elegans ... 73 
 
 PLATE VIII. 
 
 1 Neretina fluviatilis 16 
 
 2 Assiminia Grayana ... 19 
 
 3 Paludina Listeri 17 
 
 4 Planorbis albus 60 
 
 5 Succinea putris 57 
 
 6 Helix Cantiana 32 
 
 7 Conovulus denticulatus. 72 
 
 8 Cyclas cornea 8 
 
 9 Cyclostoma elegans ... 73 
 
 10 Limnseus auricularius .. 67 
 
 11 Anodonta cygnea ...14, 15 
 
A FEW JIEMAliKS 
 
 ON THE 
 
 C O L L E C T I N G OF SHE L L S , 
 
 FOR OUK YOUNGER READERS. 
 
 ALTHOUGH the descriptions and observations under 
 each species, would, perhaps, be sufficient to enable the 
 Conchologist readily to discover and name them ; we 
 have thought a few remarks, addressed more especially 
 to our younger readers, in a simple manner, might be 
 of use in conveying some hints of a practical character, 
 which could not be so well introduced, in any other way. 
 We will, therefore, take an imaginary conchological 
 trip. 
 
 What a merry company we are, on this our first hunt 
 after shells. " I wonder how many we shall find ?" says 
 one ; " I can't imagine what they are like, " replies his 
 companion, " unless they are those striped snails which 
 we find in the hedge banks ; but here comes Cousin 
 William, who will tell us all about them ; " whereupon, 
 with many a pleasant joke and merry laugh, we make 
 our way to the nearest stream, dash in our spoons with 
 impatient ardour, and having brought up a quantity of 
 mud from the bottom, look into the slimy mass in dis- 
 pair. Oh ! Cousin William, how could you bring us 
 to such a spot as this ; who can find any shells among 
 this filthy stuff ? " Patience, my dear boy, shake it about 
 well in the water to clear off the mud, and you will 
 most likely find what you want left behind ; next time, 
 
 G 
 
82 
 
 however, you apply your spoon, put it in a little more 
 gently, and scrape off the top of the mud only, or run 
 it through the plants in the middle of the stream, or 
 amongst the grass on the margin, and you will obtain 
 that for which you are searching, without all the labour 
 you are now giving yourself. " Having followed out 
 our instructions, after a deal of labour by our unskilful 
 hands, we soon perceive some light coloured objects, 
 which, upon close inspection, turn out to be shells. 
 " Oh ! what lovely little things, " we all exclaim in a 
 breath, " see, they are double shells ! " 
 
 Being now fairly in quest of these inhabitants of the 
 stream, we quickly fill some of our boxes with the 
 bivalves, and with one or two kinds of univalves. The 
 first excitement is after a while somewhat over, and we 
 sit down upon some grassy knoll to look over our spoils. 
 Cousin William is applied to for information respecting 
 them ; he explains to his young companions that the 
 bivalves first found belong to the order Conchifera ; 
 that they are called Cyclas Cornea ; that there are three 
 species included under the head Cyclas, and a variety 
 of other information respecting them. He next shews 
 them some of the other smaller bivalves, allied to the 
 Cyclas, but under another family, named Pisidium 
 the one they have found being Pisidium amnicum. 
 " Whatever is this ! " exclaims a youthful member of 
 our party, " see what a slimy looking animal protrudes 
 himself from the large opening !" This turns out to be 
 Limnceus pereger, the most widely distributed of our 
 water shells, and though by no means the most attrac- 
 tive-looking object, it improves on acquaintance. " You 
 have overlooked this pretty little shining fellow, " re- 
 marks their interesting instructor, " it is the ' bubble 
 
 G 2 
 
83 
 
 shell,* Physa fontinalis 'take care, or you will break 
 it, it is too fragile to be roughly handled. " Some other 
 curious looking shells are next brought under review ; 
 they are all flat, and consist of five or six whorls close 
 together, very much like a minute snake when coiled 
 up ; these, they are informed, belong to the genus 
 Planorbis, the larger one being marginatus, and the 
 smaller and thinner ones, vortex. 
 
 On our next trip, though the novelty is not so great 
 as before, we set out with redoubled zeal, puffed up 
 With the consciousness of having no small acquaintance 
 with what we are about. Our first dip affords us some 
 of our former acquaintances, but nothing new rewards 
 our search ; so we pass on to a small pond, which has 
 been espied by one of our party, in the corner of a 
 large field. " Did you ever see such a huge fellow ! " 
 calls out one of our juvenile band, throwing down his 
 spoon, and rushing with outstretched hands to Cousin 
 William, who seems no less pleased than his young 
 friend, to meet with what he informs him belongs to the 
 same family as Limnceus pereger, giving it the name of 
 Limnceus stagnalis. It does not require very minute 
 search to observe quite a number of them floating about 
 with their broad expanded foot upward on the surface 
 of the water, nor does it take long to obtain a sufficient 
 supply. Whilst examining our prizes more carefully, 
 and admiring their beautiful tapering forms, we find ad- 
 hering closely to their surface, a small oblong limpet- 
 like shell, which Cousin William calls Ancylus oblongus, 
 and informs us that a commoner species, Ancylus flu- 
 matilis, may be generally found in clear running streams 
 adhering to stones, wood, &c. 
 
 One earnest member of our company expecting, or 
 
wishing, to lind nearly all the different species within 
 the narrow limits of a single pond, exclaims with a 
 rather disappointed air, " I have searched and searched, 
 but cannot find a single Limnceus pereger. " This, he 
 is told, is by no means an uncommon thing, though the 
 reason is less easily given ; he is also informed, that 
 frequently in the same stream, in one part nearly all 
 shells are of a species differing from those inhabiting 
 another. At the bottom of one slowly flowing stream, 
 several large bivalves are pointed out to us, sunk 
 almost over-head in mud; these turn out to be Ano- 
 donta Cygnea. With no little eagerness we apply our 
 spoons, but without much effect, except upon those 
 which are tenantless ; looking to our preceptor, who is 
 smiling at our attempts, we entreat him to help us, but 
 he shakes his head, and says we must move on to a 
 part of the stream which is clearer than that we have 
 disturbed. Here we watch him quietly plunge the 
 handle of his spoon into the water, and insert it be- 
 tween the valves of one of these shells, and draw it 
 out again with it firmly attached to the end. 
 
 Our next Conchological excursion, we are informed, 
 is to be confined more particularly to those which in- 
 habit woods, and hedge-rows ; and we set out without 
 any definite idea as to what we are likely to meet with. 
 The first convenient mossy bank is, however, submitted 
 to a search ; down we drop on our knees, pull aside the 
 leaves and stems of the plants, and after diligent search, 
 we find several species, chiefly of the Helix and Zonites 
 tribe ; Pupa umbilicata and also Bulimus obscurus are 
 added to our stock, though but sparingly. Thence we 
 proceed to a wood of more ancient growth, where the 
 soil, for some depth, is little else than a carbonaceous 
 
85 
 
 deposit of decayed vegetable matter ; here, so numerous 
 are the different species, that we have neither time nor 
 ability to make any classification of them, so depositing 
 them in some of our boxes, having more regard to their 
 size than specific distinctions, being afraid if we mix the 
 smaller with the larger, that they may be lost or injured. 
 
 Following the guidance of our leader, we traverse 
 the wood in all directions ; now examining the roots of 
 plants ; now carefully scanning the stems and leaves of 
 the dense masses of ferns, Equisetse, and the larger 
 herbaceous plants, with which the place is crowded, for 
 the more conspicuous of the Helices and Succineaputris. 
 Nor do we forget to pry in the bark, and beneath the 
 Lichens which clothe the stems of the huge oaks around 
 us, being assured that we shall most probably be re- 
 warded with some of the Clausilia tribe, or, perhaps, 
 Balea fragilis. Coming to an old stump, we are advised 
 to examine it well, as it will most likely afford us some 
 interesting specimens, and sure enough, we have not 
 been long busily engaged amongst the moss which 
 clothes its decayed sides, before one of our party ex- 
 claims exultingly, " I have it, I have it ! " and exhibits 
 to our eager and enquiring gaze the most elegant land 
 shell we have yet found, Clausilia laminata, and we 
 seem as though we could scarcely cease admiring its 
 deep pellucid chocolate colour, the gracefulness of its 
 swelling outline, and the curious wavy tooth which 
 protects its mouth. Several others are found, and we 
 wend our way homewards. 
 
 Living within a few miles of the sea coast, and un- 
 derstanding there are a number of Land Shells to be 
 found upon the sand-hills in the neighbourhood of the 
 sea, it is not long before we determine upon an excur- 
 
86 
 
 sion thither. Accordingly, one fine day, we might be 
 seen exploring most earnestly what might seem to many 
 persons the most uninteresting locality imaginable ; we, 
 however, do not find it so, for we are quite surprised at 
 the immense number of Helix virgata, ericetorum, 
 Cantiana, and caperata, which find their subsistence 
 upon the low stunted vegetation. In one part, too, we 
 come upon a numerous family of Pupa muscorum, and 
 at other places meet with Helix hispida, variety depilata, 
 and have some of our notions of specific difference 
 rather shaken, by being told that it is not a distinct 
 species. 
 
 A piece of marshy ground in the neighbourhood is 
 next explored; there we find the first specimens of 
 Conovulus we have seen, which, though placed among 
 the Land Shells, or rather, perhaps, the amphibious 
 ones, seems to prefer situations where the water is 
 slightly brackish. Proceeding onwards in our search, 
 we come to the margin of a considerable stream, on 
 whose banks there is a quantity of rejectmenta, or 
 "wreck," as it is sometimes called, which has been 
 brought down by a flood ; this, when examined, proves 
 to be rich in the empty homes of several species of 
 mollusks, some of which we have not seen before. A 
 portion is taken home, to be examined at leisure. Thus 
 an excursion which might have seemed at first likely 
 to afford little that would interest one in the search 
 of Land shells merely, turns out to be more than 
 usually productive, and many leisure hours are em- 
 ployed, in cleaning, naming, and arranging those which 
 we have thus procured. 
 
 Many are the instructive lessons we receive respecting 
 the habits and economy of the different tribes ; their 
 
internal structure is also a subject of a good deal of 
 interest. The stomach of one of the larger ones is 
 exhibited to our wondering eyes, and shown, under the 
 microscope, to be lined by a thin gizzard-like membrane, 
 armed with some thousands of horny teeth, for the 
 purpose of masticating the food ; the stomach being set 
 in motion by a large muscle. 
 
 The pulsation of the heart of these creatures is 
 watched with great interest, and one or two instructive 
 experiments are made upon them. A large specimen of 
 Limax cinereus is first obtained, and being placed on a 
 plate, or some shallow vessel, is allowed free liberty of 
 action ; this he presently takes advantage of, and stretch- 
 ing himself to his full length, begins his peregrinations ; 
 almost simultaneously with this we perceive his breath- 
 ing hole expand, displaying all the internal structure 
 of that part of the body just beneath the mantle ; the 
 lungs and the heart are easily discernible. Wishing for 
 a closer inspection of these, we apply our magnifying 
 glasses, and thus perceive a sight which astonishes us. 
 The whole arrangement of the heart, with its network 
 of arteries and veins, is rendered quite distinct, and by 
 careful observation, we can discern the repeated filling 
 and emptying of these, as the muscles of the heart 
 expand or contract; counting the strokes we find that 
 Limax cinereus has a pulsation of 60 or 70 strokes per 
 minute, and this we find to be the ordinary rate of most 
 other land mollusks, under a temperature of about 
 60 Fahrenheit. 
 
 We next place under review several different species 
 of the most transparent Zonites, examining them with 
 a pocket lens. The heart is best seen when the shell 
 is placed with the under surface upwards ; the pulsation 
 
88 
 
 is very distinctly discernible, though the arteries can 
 scarcely be seen on account of the thickness of the shell 
 intervening. The number of strokes is as above men- 
 tioned when the shell is placed on the table, but we no 
 sooner take it into our hands, than its pulsation is in- 
 creased to an almost feverish rapidity, and we count 
 upward of 100 strokes per minute. This seems really 
 marvellous, and we immediately exclaim, " What can 
 be the cause of this ? it cannot arise from fear, it surely 
 must be the heat of the hand ; " so, in order to test the 
 the truth of this surmise, we prepare a cooling mixture, 
 and place our subject so that it may be affected by the 
 cold without being wetted. Our theory is verified, for 
 in a very few seconds their pulsations seem almost to 
 cease, or to go on so languidly as to make it difficult to 
 count the strokes ; probably they may not be more 
 than 20 per minute. But we soon perceive the benefit 
 that is to result from such a provision ; it is one of the 
 many evidences of design on the part of an all-wise 
 Creator, with which the animal kingdom abounds. 
 During the winter, mollusks hybernate, and remain for 
 several months in a state of torpor, without partaking 
 of any nourishment, as is evident, since they seal up 
 the entrance of their domain at the commencement 
 of severe weather, and do not come forth until the 
 warmth of spring calls them into more active existence. 
 How important, then, that as little waste as possible 
 should go on during that period ; and in no other way 
 could this be brought about so effectually as in having 
 the circulation decreased to such a degree as almost to 
 cease during the severity of the winter season. 
 
PI. I. 
 
n. 
 
II, IV. 
 
PL V 
 


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 BIOLOGY 
 UBRARY