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Full text of "Our country's shells and how to know them : a guide to the British mollusca"

:-NRLF 



OUR COUNTRY'S 
SHELLS 




WJ.GORDON 




THE LIBRARY 

OF 

THE UNIVERSITY 
OF CALIFORNIA 

PRESENTED BY 

PROF. CHARLES A. KOFOID AND 
MRS. PRUDENCE W. KOFOID 



FRONTISPIECE 



PLATE 22 



L> 



341 




OUR COUNTRY'S SHELLS 



AND 



How TO KNOW THEM. 

H (Suifce to tbe JSrftfsb flDollusca, 



W. J. GORDON, 

AUTHOR OF "OUR COUNTRY'S FLOWERS," "OUR COUNTRY'S BIRDS, 

" OUR COUNTRY'S BUTTERFLIES AND MOTHS," 

ETC. 



WITH A COLOURED ILLUSTRATION OF EVERY SPECIES, 
AND MANY ORIGINAL DIAGRAMS, 

BY 

A. LAMBERT. 



LONDON : 
SIMPKIN, MARSHALL, HAMILTON, KENT & CO., LIMITED. 



OUR COUNTRY'S SERIES, 

BY W. J. GORDON. 

Each with 33 Coloured Plates and other 
Illustrations. Crown 8vo, 6/- each, 

OUR COUNTRY'S FLOWERS AND How 
TO KNOW THEM. A Complete Guide to 
the Flowers and Ferns of Great Britain. 

OUR COUNTRY'S BIRDS AND How TO 
KNOW THEM. A Guide to all the Birds 
of Great Britain. 

OUR COUNTRY'S BUTTERFLIES AND 
MOTHS AND How TO KNOW THKM. 
A Guide to the Lepidoptera of Great 
Britain. 

OUR COUNTRY'S SHELLS AND How 
TO KNOW THKM. A Guide to the 
British Mollusca. 



. [5 ,o f 
INTRODUCTION. 



HP HIS book, like the rest of the series, is intended as an 
-*- introductory working manual for the collector, the object 
of its analytical tables being to enable him to name any specimen 
in the British list without reading more than is needful for that 
one purpose. It is on the same principle as its predecessors. In 
the Flowers we dealt with a natural kingdom ; in the Birds with 
a natural class, in the Butterflies and Moths with a natural order ; 
in this volume we are dealing with a natural sub-kingdom, so that 
we have had an example of each of the four highest systematic 
groups treated on the same plan. 

Every living species of the sub-kingdom generally claimed as 
a native of our country is here sufficiently described to distinguish 
it from the rest, whether it has a shell or not ; thus rather a wider 
range is covered than the main title would indicate, as many of 
the mollusca do not have shells. The coloured plates include all 
the species having shells, and these are drawn the size of life or 
enlarged in the case of those too small to be clearly shown and 
then their natural dimensions are given alongside. 

Of those without shells a representative of each genus is figured. 
The sea-slugs are given in colour, and are either of the natural 
size or enlarged. The cuttle-fishes are illustrated in two full-page 
plates, but it need hardly be said have had to be reduced ; indeed 
it would have been difficult to draw them to full scale, particularly 
if we had followed the lead of one enthusiast and included Archi- 
Uuthls among the British genera, on the strength of the specimen 
captured off the Irish coast which had tentacles thirty feet long, 
mandibles four inches across, and eyes fifteen inches in diameter. 

There is no species of the mollusca solely British except perhaps 
Limntza, involuta, which comes from a pool on the Cromagaun 
mountain, near Killarney, and is consequently Irish ; but even this 
is regarded by some as a variety. The other land species occur 



IV INTRODUCTION. 

throughout Northern Europe and Asia, and the sea species on 
almost every coast of the North Sea and along the eastern half of 
the North Atlantic. Some are found much further away. lanthina, 
the most beautiful of our univalves, comes drifting to us across the 
wide ocean, and is known all the way from Patagonia. 

A mollusc is British if it has been dredged up in British seas 
or found alive in any part of the British Isles. Thus a good wide 
net is spread for stragglers, and nationality seems to have been 
occasionally determined by the arrival of an individual in a gale of 
wind. This is inevitable, but it should be remembered that most 
of the mollusca are dioecious, though some are monoecious, and 
among the bivalves the same genus may have the sexes of its 
species distinct or combined. For instance, the British oyster is 
monoecious, but the American oyster is dioecious, and when trans- 
planted to this country has to have both sexes brought across 
the Atlantic. 

This oyster is one of several cases of successful acclimatisation, 
though mollusca are not so easily settled in strange lands as might 
be supposed. The fact that nineteen of our land shells have taken 
up their abode in Australia merely shows that a few species are 
capable of thriving almost anywhere. There are British snails in 
most ports frequented by British ships ; they travel in the packages 
and packing materials. Foreigners evidently come here in a similar 
way, and some of our novelties are traceable to nursery gardens, to 
which they have been imported in the mould around the roots of 
the plants. But no matter how they came or how widely they may 
be distributed over the world, they are British if they are found 
here, and thus our country's mollusca number over 700 species, 
with perhaps three times as many varieties. 

W. J. G. 



CONTENTS, 



CHAP. PAGE 

I. LOCAL AND POPULAR NAMES i 



II. THE COLOURED PLATES 



Plate I., figures i to 18. 

NUCULIDM, ANOMIID&, ARCADE. 

Plate II., figures 19 to 29. 
MYTILID&. 

Plate III., figures 30 to 34. 

AVICULID&, OSTREIDM, PECTINID&. 

Plate IV.. figures 35 to 43. 
PECTINIDJE. 

Plate V., figures 44 to 54. 

LIMIDJE, CARDITID&, ASTARTID&, CYPRINIDJE. 

Plate VI., figures 55 to 58. 
UNIONIDsE. 

Plate VII., figures 59 to 90. 

UN ION ID M, DREISSENSIID&, LUCINIDM, 

ERYCINID&, GALEOMMWm, CYR&NIDM, 
TELLINID&. 

Plate VIII., figures 91 to 106. 

TELLINID&, SCROBICULARIIDjE, DON ACID &. 

Plate IX., figures 107 to 117. 
MACTRID&, VENERID&. 

Plate X., figures 118 to 128. 

VENERIDM, PETRICOLID&. 

Plate XI., figures 129 to 138. 
CARDIIDM. 

Plate XII., figures 139 to 148. 
PSAMMOBIID&, MYIDJE. 

Plate XIII., figures 149 to 155. 
SOLENID&. 



VI CONTENTS. 

THE COLOURED PLATES Continued. 

Plate XIV., figures 156 to 171. 

GLYCIMERWSE, GASTROCHCENID&, PHOLADID&, 
TEREDINID&. 

Plate XV., figures 172 to 189. 

PANDORID&, LYONSHD^E, ANATINID&, 
POROMYID&, DENTALIIDM. 

Plate XVI., figures 190 to 200. 
CHITON ID &. 

Plate XVII., figures 201 to 229. 

AURICULID^E, OTINID^E, LIMN&ID32, PHYSIDM. 

Plate XVIII. , figures 230 to 246. 

TESTACELLID&, LIMACIDM. 

Plate XIX., figures 247 to 278. 
HELICID&. 

Plate XX., figures 279 to 318. 

HEL1C1DM, PUPID&, STENOGYRID&, 
SUCCINEID&, ONCHIDIIDM. 

Plate XXI., figures 319 to 337. 

ACM&W&, LEPETID&, PATELLID/E, 
FISSURELLID&, HALIOTID&, 
PLEUROTOMARIID&, CYCLOSTREMA TIDsE. 

Plate XXII., figures 338 to 369. 

TROCHID&, TURBINID&, NER1TID&, 
IANTHINID&, SCALARIIDM. 

Plate XXIII., figures 370 to 399. 

NATICID&, LAMELLARllDM, TRICHOTROPW&, 
CAPULID/E, HOMALOGYRID&, 
L1TTORINID&, CYCLOSTOMATID&, 
ACICULID&, TRUNCATELLIDM. 

Plate XXIV., figures 400 to 451. 

R1SSOID&, HYDROBIIDJE, ASSIMINEID^E, 

SKENEIDM, JEFFREYSIIDJE, ADEORBIDJE, 
VIVIPARIDM, VALVATID&, CERITHIID^E. 

Plate XXV., figures 452 to 467. 

TURRITELLIDM, CJECIDJE, APORRHAIDM, 
CYPRJEID1E, TRITON ID M t EULIMIDJE. 

Plate XXVI., figures 468 to 516. 

PYRAMIDELLID&, MURICID&, COLUMBELL1DM, 
NASSIDJE. 



CONTENTS. Vi 

THE COLOURED PLATES Continued. 

Plate XXVII., figures 517 to 520. 

BUCCINID&, FASCIOLARIID&. 

Plate XXVIII., figures 521 to 525 
FASCIOLARUDM. 

Plate XXIX., figures 526 to 549. 

FASCIOLARIIDM, MARGINELLID&, CONIDJE. 

Plate XXX., figures 550 to 585. 

ACTIEONID/E, TORNATINIDM, SCAPHANDRIDM, 
BULLID&, PHILINID&, APLYSIIDM, 
PLE UROBRA NCHID&, R UNCINID&, 
LIMACINWJS, CAVOLINIIDJE, CLIONID&. 

Plate XXXI., figures 586 to 596. 

HERM&ID&, ELYSIIDJS, LIMAPONTIIDM, 
JEOLIDIDIE. 

Plate XXXII., figures 597 to 602. 

LOMANOTID&, DOTONID&, DENDRONOTID&, 
SCYLLMID&, PLEUROPHYLLIDIID&, 
TR1TONIID&. 

Plate XXXIII., figures 603 to 611. 

DORIDIDJE, POLYCERIDM, GONIODORID&. 

III. CUTTLE FISHES . . 25 

IV. MULTIVALVES AND BlVALVES 30 

V. UNIVALVES 47 

VI. TABULAR SCHEME 66 

VII. IDENTIFICATION . . . . . . . . 74 

VIII. GLOSSARY 78 

IX. CLASSES, ORDERS, AND SUB-ORDERS .... 82 

X. ORDERS AND FAMILIES 85 

XI. FAMILIES AND GENERA ....... 95 

XII. GENERA AND SPECIES 106 

XIII. LIST OF SPECIES 146 



DIAGRAMS, 



PAGE 

BRITISH CUTTLE FISHES 26 

BRITISH CUTTLE FISHES .*..... 27 
PARTS OF A MULTIVALVE SHELL . . . . -30 
PARTS OF A BIVALVE SHELL . . . . . -31 
LEFT VALVE OF Unio pictorum . . . . -32 
PARTS OF AN OYSTER (Ostrea edulis) . . . .40 

PARTS OF A UNIVALVE SHELL (Nassa reticulata) . . 52 

VARIETIES OF THE MOUTH 53 

LIVING SHELLS 56 



CHAPTER I. 

LOCAL AND POPULAR NAMES, 



w 

THE numbers in this list refer to the coloured plates, and 
are those adopted throughout the book. 


Amber Snail, 313-317. 


Capped Cyclas, 82. 


Dog- Whelk, 513-516. 


Succinea (the genus). 


Sphaerium lacustre. 


Nassa (the genus). 


Anodon, 58, 59. 


Cheese Snail, 277. 


Dove Shell, 511, 512. 


Anodonta (the genus). 


Helix obvoluta. 


Columbella (the genus). 


Apple Snail, 279. 

Helix pomatia. 


Chrysalis Snail, 288-291. 
Pupa (the genus). 


Ear Shell, 333. 
Haliotis tuberculata 


Ark, n-15. 
Area (the genus). 


Clam, 143. 

Mya arenaria. 


Eight- Whorled Mud 
Shell, 208. 
Limnaea glabra. 


Banded Cockle, 134. 






Cardium fasciatum. 


Cockle, 136. 
Cardium edule. 


Field Slug, 235. 






Limax agrestis. 


Banded Snail, 276-278. 
Helix nemoralis and Helix 
pisana. 


Cockle, BrUlion, 143. 

Mya arenaria. 


File Shell, 44-48. 
Lima (the genus). 


Barnagh, 520. 


Coil Snail, 215-226. 




Fusus antiquus. 


Planorbis (the genus). 


Fresh - water Limpet, 

205, 206. 


Bearded Mussel, 21. 


Cowry, 457. 


Ancylus (the genus). 


Mytilus barbatus. 


Cypraea europaea. 


Gaper, 143-148. 


Black Mussel, The, 55. 

Unio margaritifer. 


Cup-and-Saucer Limpet, 

383. 
Calyptraea chinensis. 


Mya (the genus), Corbula 
gibba, Lutraria (the 
genus). 


Black Slug, 241. 
Arion ater. 


Cyclas, Capped, 82. 


Garden Slug, 244. 

Arion hortensis. 




Sphasrium lacustre. 




Bonnet Limpet, 383. 




Garden Snail, 273 


Calyptrasa chinensis. 


Cyclas, Horny, 81. 


Helix hortensis. 


Bonnet, Torbay, 382. 
Capulus hungaricus. 


Sphaerium corneum. 
Cyclas, Oval, 83. 


Garlic Snail, 249. 

Zonites alliarius. 


Brown Slug, 236. 
Limax lasvis. 


Sphasrium ovale. 
Cyclas, River, 84. 


Glass Snail, 247. 
Vitrina pellucida. 


Bubble Shell, 227-229, 565- 

567. 


Sphaerium rivicola. 
Dog Cockle, The, 16. 


Gowrie, 457. 
Cypraea europaea. 


Physa (the genus) and 
Bulla (the genus). 


Pectunculus glycimeris. 


Green Snail, 282. 
Helix revelata. 




Dog Periwinkle, 344, 508. 




Buckle, 520. 


Trochus cinerarius and 


Heart-Cockle, 54. 


Fusus antiquus. 


Purpura lapillus. 


Isocardia cor. 



LOCAL AND POPULAR NAMES. 



Horny Cyclas, 81. 


Mussel, Swollen Fresh- 


Razor Fish, 152-155 


Sphaerium corneuin. 


water, 57. 


Solen (the genus). 




Unio tumidus. 




Horse Mussel, 20. 




Razor SheU, 149-155. 


Mytilus modiolus. 

Irish Slug, 246. 


Mussel, Zebra, 60. 

Dreissensia polymorpha. 


Solecurtus (the genus), 
Ceratisolen (the genus), 
and Solen (the genus). 


Geomalacus maculosus. 


Notched Limpet, 329. 


Red Whelk, 520. 


Keeled Slug, 233. 


Emarginula fissura. 


Fusus antiquus. 


Amalia marginata. 

KentisV Snail, 266. 


Nut SheU, 1-4. 
Nucula (the genus). 


River Cyclas, 84. 

Sphaerium rivicola. 


Helix cantiana. 


Old Maid, 143. 


River Limpet, 206. 




Mya arenaria. 


Ancylus fluviatilis. 


Keyhole Limpet, 326-328. 






Fissurella (the genus) and 


Ormer, 333. 


Rock Limpet, 324. 


Puncturella (the genus). 


Haliotis tuberculata. 


Patella vulgata. 


Land Sole, 241. 


Otter Shell, 147, 148. 


Scallop, 43. 


Arion ater. 


Lutraria (the genus). 


Pecten maximus. 


Limpet, 324. 


Oval Cyclas, 83. 


Sea Hare, 577-579. 


Patella vulgata. 


Sphaerium ovale.- 


Aplysia (the genus). 


Limpet, Bonnet, 383. 


Oyster, 32. 


Sea Lemon, 662-683. 


Calyptraea chinensis. 


Ostrea edulis. 


Doris (the genus). 


Limpet, Cup-and-Saucer, 


Painters' Mussel, 56. 


Shining Pisidium, 87. 


383. 
Calyptrasa chinensis. 


Unio pictorum. 


Pisidium nitidum. 


Limpet, Fresh water, 

205, 206. 


Papier Mache SheU, 333. 

Haliotis tuberculata. 


Shipworm, 166-171. 
Teredo (the genus). 


Ancylus (the genus). 


Pearl Mussel, The, 55. 


Six-toothed Whorl SheU, 

301. 


Limpet, Keyhole, 326-328. 


Unio margaritifer. 


Vertigo substriata. 


Fissurella (the genus) and 
Puncturella (the genus). 

Limpet, Bock, 324. 


Pelican's Foot, 455. 
Aporrhais pes-pelecani. 


Sliggaun, 59. 
Anodonta cygnea. 


Patella vulgata. 


Perforated Limpet, 328. 


Spindle SheU, 520. 


Looping Snail, 399. 


Puncturella noachina. 


Fusus antiquus. 


Truncatella truncatula. 


Periwinkle, 387-391. 


Spout SheU, 455. 


Marsh Shell, 440. 


Littorina (the genus). 


Aporrhais pes-pelecani. 


Viviparus vivipara. 








Periwinkle, Dog, 344, 508. 


Sting Winkle, 506. 


Milky Slug, 235. 


Purpura lapillus, and Tro- 


Murex erinaceus. 


Limax agrestis. 


chus cinerarius. 








Striped Sunset, The, 141. 


Mussel, 19-23. 


Pheasant Shell, 355. 


Psammobfa ferroensis 


Mytilus (the genus). 


Phasianella pulla. 








Sunset SheU, 139-142. 


Mussel, Black, 55. 


Piddock, 160-163. 


Psammobia (the genus). 


Unio margaritifer. 


Pholas (the genus). 




Mussel, Painters', 56. 

Unio pictorum. 


Pigmy Cockle, 133. 

Cardium exiguum. 


Swan Mussel, 59. 

Anodonta cygnea. 






Swollen Fresh water 


Mussel, Pearl, 55. 


Pinpatch, 390. 


Mussel, 57. 


Unio margaritifer. 


Littorina littorea. 


Unio tumidus. 


Mussel, Swan, 59. 


Pond Snail, 207-214. 


TeUen, 90-97. 


Auodonta cygnea 


Limnaea (the genus). 


Tellina (the genus). 



LOCAL AND POPULAR NAMES. 



Tender Slug, 237. 


Wedge Shell, 104-106. 


Whorl Snail, 292-302. 


Limax tenellus. 


Donax (the genus). 


Vertigo (the genus). 


Tooth Shell, 184-189. 
Siphonodentalium (the 
genus), Cadulus (the 


Wentletrap, 360-364. 

Scalaria (the genus). 


Wood Snail, 276. 
Helix nemoralis. 


genus), and Dentalium 






(the genus). 


Whelk, 517, 518, 520. 


Wrinkled Snail, 267. 


Torbay Bonnet, 382. 
Capulus hungaricus 


Buccinum (the genus) and 
Fusus antiquus. 


Helix caperata. 


Vine Snail, 279. 

Helix pomatia. 


Whelk, Red, 520. 
Fusus antiquus. 


Yellow Slug, 234. 
Limax flavus. 


Violet Sea-Snail, 357-359. 


White Snail, 280. 


Zebra Mussel, 60. 


lanthina (the genus). 


Helix pulchella. 


Dreissensia polymorpha. 



THE COLOURED PLATES. 



CHAPTER II. 

THE COLOURED PLATES, 



THE numbers inset are those of the land and fresh-water 
species. The bringing of the bivalves to the front and 
putting the pulmonates immediately after the chitons is not an 
attempt at a new classification. It is simply the arrangement 
which was eventually found convenient for the grouping of the 
illustrations. 

PELECYPODA. 

PROTOBRANCHIATA. 

NUCULIDJE. 

Plate I. i. NUCULA SULCATA. 

2. NUCULA NUCLEUS. 

3. NUCULA NITIDA. 

4. NUCULA TENUIS. 

5. LEDA PYGM^A. 

6. LEDA LUCIDA. 

7. LEDA MINUTA. 

8. LEDA PERNULA. 

FILIBRANCHIATA. 

ANOMIACEA. 

ANOMIHXE. 

9. ANOMIA EPHIPPIUM. 

10. ANOMIA PATELLIFORMIS. 

ARCACEA. 

ARCAD.fi. 

11. ARCA PECTUNCULOIDES. 

12. ARCA OBLIQUA. 

13. ARCA LACTEA. 

14. ARCA TETRAGONA. 

15. ARCA NODULOSA. 

16. PECTUNCULUS GLYCIMERIS. 

17. LIMOPSIS AURITA. 

18. LIMOPSIS BOREALIS. 



THE COLOURED PLATES. 



MYTILACEA. 



Plate II. 



MYTILID^. 

19. MYTILUS EDULIS. 

20. MYTILUS MODIOLUS. 

21. MYTILUS BARBATUS. 

22. MYTILUS ADRIATICUS. 

23. MYTILUS PHASEOLINUS. 

24. CRENELLA RHOMBEA. 

25. CRENELLA DECUSSATA. 

26. MODIOLARIA MARMORATA. 

27. MODIOLARIA COSTULATA. 

28. MODIOLARIA DISCORS. 

29. MODIOLARIA NIGRA. 



PSEUDOLAMELLIBRANCHIATA. 



Plate III. 



Plate IV. 



Plate V. 



AVICULID/E. 

30. AVICULA HIRUNDO. 

31. PINNA RUDIS. 

OSTREIDJE. 

32. OSTREA EDULIS. 

PECTINIDJE. 



33- 

34- 
35- 
36. 
37- 
38. 
3<J- 
40. 
41. 
42. 
43- 


PECTEN 
PECTEN 
PECTEN 
PECTEN 
PECTEN 
PECTEN 
PECTEN 
PECTEN 
PECTEN 
PECTEN 
PECTEN 


PUSIO. 
VARIUS. 
OPERCULARIS. 
SEPTEMRADIATUS. 
TIGRINUS. 
TESTAE. 
STRIATUS. 
SIMILIS. 
ARATUS. 
VITREUS. 
MAXIM US. 



UUXDM. 

44. LIMA SARSII. 

45. LIMA ELLIPTICA. 

46. LIMA SUB-AURICULATA. 

47. LIMA LOSCOMBII. 

48. LIMA HIANS. 



EULAMELLIBRANCHIATA. 

SUBMYTILACEA. 



CARDITID^E. 

49. CYAMIUM MINUTUM. 



THE COLOURED PLATES. 

PLATE V. (continued) 

ASTARTIDJE. 

50. ASTARTE SULCATA. 

51. ASTARTE COMPRESSA. 

52. ASTARTE TRIANGULARIS. 

CYPRINIDJE. 

53. CYPRINA ISLANDICA. 

54. ISOCARDIA COR. 



Plate VI. 



Plate VII. 



UNIONIDJE. 

55. UNIO MARGARITIFER. 

56. UNIO PICTORUM. 

57. UNIO TUMIDUS. 

58. ANODONTA ANATINA. 

59. ANODONTA CYGNEA. 

DREISSENSIHXffi. 

60. DREISSENSIA- POLYMORPHA. 



LUCINIDJE. 

61. LUCINA SPINIFER. 

62. LUCINA BOREALIS. 

63. LORIPES LACTEUS. 

64. LORIPES DIVARICATUS. 

65. DIPLODONTA ROTUNDATA. 

66. AXINUS FLBXUOSUS. 

67. AXINUS CROULINENSIS. 

68. AXINUS FERRUGINOSUS. 

69. MONTACUTA SUBSTRIATA. 

70. MONTACUTA BIDENTATA. 

71. MONTACUTA TUMIDULA. 

72. MONTACUTA FERRUGINOS.' 

ERYCINIDJE. 

73. KELLIA SUBORBICULARIS. 

74. KELLIA CYCLADIA. 

75. LASJEA RUBRA. 

76. LEPTON SQUAMOSUM. 

77. LEPTON NITIDUM. 

78. LEPTON SULCATULUM. 

79. LEPTON CLARKI.E. 

GALEOMMIDJE. 

80. GALEOMMA TURTONI. 

CYR.ENID.ffi. 

81. SPH^RIUM CORNEUM. 

82. SPH^RIUM LACUSTRE. 

83. SPH^RIUM OVALE. 



THE COLOURED PLATES. 

PLATE VII (continued) 

84. SPH^RIUM RIVICOLA. 

85. PISIDIUM AMNICUM. 

86. PISIDIUM FONTINALE. 

87. PISIDIUM NITIDUM. 

88. PISIDIUM PUSILLUM. 

89. PISIDIUM ROSEUM. 

TELLINACEA. 

TELLINIDJE. 

90. TELLINA BALAUSTINA. 

Plate VIII. (Front.) 91. TELLINA CRASSA. 

92. TELLINA BALTHICA. 

93. TELLINA TENUIS. 

94. TELLINA FAB U LA. 

95. TELLINA SQUALIDA. 

96. TELLINA DONACINA. 

97. TELLINA PUSILLA. 

98. GASTRANA FRAGILIS. 

SCROBICULARinXffi. 

99. SCROBICULARIA PRISMATICA. 

100. SCROBICULARIA NITIDA. 

101. SCROBICULARIA ALBA. 

102. SCROBICULARIA TENUIS 

103. SCROBICULARIA PIPERATA 

DONACIDJE. 

104. DONAX VITTATUS. 

105. DONAX TRUNCULUS. 

106. DONAX POLITUS. 

MACTRIDJE. 
Plate IX. 107. AMPHIDESMA CASTANEUM. 

108. MACTRA SOLIDA. 

109. MACTRA ELLIPTICA. 

no. MACTRA SUB-TRUNCATA. 
in. MACTRA STULTORUM. 

112. MACTRA GLAUCA. 

VENERACEA. 

VENERIDJE. 

113. CIRCE MINIMA. 

114. VENUS EXOLETA. 

115. VENUS LINCTA. 

116. VENUS CHIONE. 

117. VENUS FASCIATA. 

Plate X. "8. VENUS CASINA. 

119. VENUS VERRUCOSA. 



THE COLOURED PLATES. 



PLATE X. (continued) 



120. VENUS OVATA. 

121. VENUS GALLINA. 

122. LUCINOPSIS UNDATA. 

123. TAPES AUREUS. 

124. TAPES VIRGINEUS. 

125. TAPES PULLASTRA. 

126. TAPES DECUSSATUS. 

127. VENERUPIS IRUS. 

PETRICOLIDJE. 

128. PETRICOLA PHOLADIFORMIS. 



CARDIACEA. 



Plate XL 



CARDIID;E. 



129. 
130. 
131- 
132. 
133. 
134- 
135- 

136. 

137- 

138. 


CARDIUM 
CARDIUM 
CARDIUM 
CARDIUM 
CARDIUM 
CARDIUM 
CARDIUM 
CARDIUM 
CARDIUM 
CARDIUM 


ACULEATUM. 
ECHINATUM. 
TUBERCULATUM. 
"RAPILLOSUM. 
EXIGUUM. 
FASCIATUM. 
NODOSUM. 
EDULE. 
MINIMUM. 
NORVEGICUM. 



MYACEA. 



Plate XII. 



PSAMMOBIIDJE. 

139. PSAMMOBIA TELLINELLA. 

140. PSAMMOBIA COSTULATA. 

141. PSAMMOBIA FERROENSIS. 

142. PSAMMOBIA VESPERTINA. 



MYHXE. 

143. MYA ARENARIA. 

144. MYA TRUNCATA. 

145. MYA BINGHAMI. 

146. CORBULA GIBBA. 

147. LUTRARIA ELLIPTICA. 

148. LUTRARIA OBLONGA. 



SOLENID.fi. 

Plate XIII. 149. SOLECURTUS CANDIDUS. 

150. SOLECURTUS ANTIQUATUS. 

151. CERATISOLEN LEGUMEN. 

152. SOLEN PELLUCIDUS. 

153. SOLEN ENSIS. 

154. SOLEN SILIQUA. 
iss. SOLEN VAGINA. 



THE COLOURED PLATES, 

GLYCIMERIDJE. 

Plate XIV. 156. SAXICAVA NORVEGICA. 

157- SAXICAVA RUGOSA. 

158. PANOP^A PLICATA. 

GASTROCH(ENIDJE. 

159- GASTROCHCENA DUBIA. 



PHOLADACEA. 

PHOLADIDJE. 

160. PHOLAS DACTYLUS. 

161. PHOLAS CANDIDA. 

162. PHOLAS PARVA. 

163. PHOLAS CRISPATA. 

164. PHOLADIDEA PAPYRACEA. 

165. XYLOPHAGA DORSALIS. 

TEREDINIDJE. 

166. TEREDO NORVEGICA. 

167. TEREDO NAVALIS. 

168. TEREDO PEDICELLATA. 

169. TEREDO MEGOTARA. 

170. TEREDO MALLEOLUS. 

171. TEREDO BIPINNATA. 



ANATINACEA. 

PANDORIDJE. 

Plate XV. 172. PANDORA IN^QUIVALVIS. 

LYONSIIDJE. 

173. LYONSIA NORVEGICA. 

ANATINIDJE. 

174- THRACIA PRvETENUIS. 

175- THRACIA PAPYRACEA. 
176. THRACIA PUBESCENS. 
177- THRACIA CONVEXA. 

178. THRACIA DISTORTA. 



SEPTIBRANCHIATA. 



POROMYIDJE. 

179- POROMYA GRANULATA. 

180. NE/ERA ABBREVIATA. 

181. NE^ERA COSTELLATA. 

182. NE^RA ROSTRATA. 

183. NE^RA CUSPIDATA. 



10 



PLATE XV. (continued) 



THE COLOURED PLATES. 



SCAPHOPODA. 

DENTALinXffi. 

184. SIPHONODENTALIUM LOFOTENSE. 

185. CADULUS SUBFUSIFORMIS. 

186. CADULUS JEFFREYSII. 

187. DENTALIUM ENTALIS. 

188. DENTALIUM TARENTINUM. 

189. DENTALIUM ABYSSORUM. 



GASTROPODA, 



AMPHINEURA. 



POLYPLACOPHORA. 



Plate XVL 



CHITONIDJE. 

190. CHITON 
tgi. CHITON 
192. CHITON 
193. CHITON 
194. CHITON 
195. CHITON 
106. CHITON 
197. CHITON 
198. CHITON 
199. CHITON 
200. CHITON 


FASCICULARIS. 
DISCREPANS. 
HANLEYl. 
CANCELLATUS. 
CINEREUS. 
ALBUS. 
MARG1NATUS. 
RUBER. 
L/EVIS. 
MARMOREUS. 
SCABRIDUS. 



PULMONATA, 

BASOMMATOPHORA. 



Plate XVII. 



AURICULIDJE. 

.201. CARYCHIUM MINIMUM 

202. MELAMPUS BIDENTATUS. 

203. MELAMPUS MYOSOTIS. 



OTINIDJE. 

204. OTINA OTIS. 



205. AXCYLUS LACUSTRIS. 

206. ANCYLUS FLUVIATILIS. 

207. LIMNJEA AURICULARIA. 

208. LIMN^EA GLABRA. 
2og. LIMN^EA GLUTINOSA. 



THE COLOURED PLATES. 

PLATE XVII. (continued} 

210. LIMN^EA INVOLUTA. 

211. LIMNvEA PALUSTRIS. 

212. LIMN^A PEREGRA. 

213. LIMN^EA STAGNALIS. 

214. LIMN/EA TRUNCATULA. 

215. PLANORBIS ALDUS. 

216. PLANORBIS CARINATUS. 

217. PLANORBIS COMPLANATUS. 

218. PLANORBIS CONTORTUS. 

219. PLANORBIS CORNEUS. 

220. PLANORBIS DILATATUS. 

221. PLANORBIS GLABER. 

222. PLANORBIS LINEATUS. 

223. PLANORBIS NAUTILliUS. 

224. PLANORBIS NITIDUS. 

225. PLANORBIS SPIRORBIS. 

226. PLANORBIS VORTEX. 

PHYS1DJB. 

227 PHYSA ACUTA. 

228. PHYSA FONTINALIS. 

229. PHYSA HYPNORUM. 

STYLOMMATOPHORA. 

TESTACELLIDJE. 
Plate XVIII. 230. TESTACELLA HALIOTIDEA. 

231. TESTACELLA MAUGEI. 

LIMACIDJE. 

232. AMALIA GAGATES. 

233. AMALIA MARGIN ATA. 

234. LIMAX FLAVUS. 

235. LIMAX AGRESTIS. 

236. LIMAX L^EVIS. 

237- LIMAX TENELLUS. 

238. LIMAX ARBORUM. 

239. LIMAX MAXIMUS. 

240. LIMAX CINEREO-NIGER. 

241. ARION ATER. 

242. ARION BOURGUIGNATI. 

243. ARION FLAVUS. 

244. ARION HORTENSIS. 

245. ARION SUBFUSCUS. 

246. GEOMALACUS MACULOSUS. 

HELICID.E. 
Plate XIX. 247. VITRINA PELLUCIDA. 

248. ZONITES DRAPARNALDI. 



12 THE COLOURED PLATES. 

PLATE XIX. (continued) 

249. ZONITES ALLIARIUS. 

250. ZONITES CELLARIUS. 

251. ZONITES CRYSTALLINUS, 

252. ZONITES EXCAVATUS. 

253. ZONITES FULVUS. 

254. ZONITES GLABER. 

255. ZONITES NITIDUS. 

256. ZONITES NITIDULUS. 

257. ZONITES PURUS. 

258. ZONITES RADIATULUS. 

259. BULIMUS ACUTUS. 

260. BULIMUS GOODALLII. 

261. BULIMUS MONTANUS. 

262. BULIMUS OBSCURUS. 

263. HELIX ACULEATA. 

264. HELIX ARBUSTORUM. 

265. HELIX ASPERSA. 

266. HELIX CANTIANA. 

267. HELIX CAPERATA. 

268. HELIX CARTUSIANA. 

269. HELIX CONCINNA. 

270. HELIX ERICETORUM. 

271. HELIX FUSCA. 

272. HELIX HISPIDA. 

273. HELIX HORTENSIS. 

274. HELIX LAMELLATA. 
275- HELIX LAPICIDA. 

276. HELIX NEMORALIS. 

277. HELIX OBVOLUTA. 

278. HELIX PISANA. 
Plate XX. 279. HELIX POMATIA. 

280. HELIX PULCHELLA. 

281. HELIX PYGM/EA. 

282. HELIX REVELATA. 

283. HELIX ROTUNDATA. 

284. HELIX RUFESCENS. 

285. HELIX RUPESTRIS. 

286. HELIX SERICEA. 

287. HELIX VIRGATA. 



PUPIDJE. 



288. PUPA MARGINATA. 

289. PUPA RINGENS. 

290. PUPA SECALE. 

291. PUPA UMBILICATA. 

292. VERTIGO ALPESTRIS. 

293. VERTIGO ANGUSTIOR. 

294. VERTIGO ANTIVERTIGO. 



THE COLOURED PLATES. 13 

PLATE XX. (continued} 

295. VERTIGO EDENTULA. 

296. VERTIGO LILLJEBORGII. 

297. VERTIGO MINUTISSIMA. 

298. VERTIGO MOULINSIANA. 

299. VERTIGO PUSILLA. 

300. VERTIGO PYGM.EA. 

301. VERTIGO SUBSTRIATA. 

302. VERTIGO TUM1DA. 

303. BALEA PERVERSA. 

304. CLAUSILIA BIPLICATA. 

305. CLAUSILIA LAMINATA. 

306. CLAUSILIA ROLPHII. 

307. CLAUSILIA RUGOSA. 

308. CLAUSILIA PARVULA. 

309. CLAUSILIA SOLIDA. 

310. COCHLICOPA LUBRICA. 

311. COCHLICOPA TRIDEXS. 

STENOGYRIDJE. 

312. ACHATINA ACICULA. 

SUCCINEIDJE. 

313. SUCCINEA ELEGANS. 

314. SUCCINEA OBLONGA. 

315. SUCCINEA PFEIFFERI. 

316. SUCCINEA PUTRIS. 

317. SUCCINEA VIRESCENS. 

ONCHIDIID/E. 

318. ONCHIDIUM CELTICUM. 



PROSOBRANCHIATA. 
DIOTOCARDIA. 
DOCOGLOSSA. 
ACMJEUUB. 

Plate XXI. 319. TECTURA TESTUDINALIS. 

320. TECTURA VIRGINEA. 

321. TECTURA FULVA. 

LEPETIDJE. 

322. LEPETA CGECA. 

323. PROPILIDIUM ANCYLOIDES. 

PATELLID^E. 

324. PATELLA VULGATA. 
335. HELCION PELLUCIPUM. 



H TH E COLOURED PLATES. 

PLATE XXI. (continued) 

RHIP1DOGLOSSA. 
FISSURELLID^E. 

326. F1SSURELLA GR/ECA. 

327. FISSURELLA GIBBA. 

328. PUNCTURELLA NOACHINA. 

329. EMARGINULA FISSURA. 

330. EMARGINULA ROSEA. 

331. EMARGINULA CRASS A. 

332. EMARGINULA CANCELLATA. 

HALIOTIDJE. 

333- HALIOTIS TUBERCULATA. 

PLEUROTOMARIHXE. 

334. SCISSURELLA CRISPATA. 


CYCLOSTREMATIDJE. 

335. CYCLOSTREMA CUTLKK1 AX UM. 

336. CYCLOSTREMA NITENS. 

337. CYCLOSTREMA SERPULOIOES. 

TROCHID^. 
Plata XXII. (Front) 



338. 


TROCHUS 


HELICIXUS. 


339- 


TROCHUS 


GRCEXLANDICUS. 


340. 


TROCHUS 


GLAUCUS. 


34i- 


TROCHUS 


AMABILIS. 


342- 


TROCHUS 


MAGUS. 


343- 


TROCHUS 


TUMIDUS. 


344- 


TROCHUS 


CINERAKIUS. 


345- 


TROCHUS 


UMBILICATUS. 


346. 


TROCHUS 


DUMINYI. 


347- 


TROCHUS 


LINEATUS. 


348. 


TROCHUS 


MONTACUTI. 


349- 


TROCHUS 


STRIATUS. 


350. 


TROCHUS 


EXASPERATUS. 


351- 


TROCHUS 


MILLEGRANUS. 


352. 


TROCHUS 


GRANULATUS. 


353- 


TROCHUS 


ZIZYPI-IINUS. 


354- 


TROCHUS 


OCCIDKNTALI3. 



TURBINIDJE. 

355. PHASIANELLA PULLA. 

NERITIDJE. 

356. NERITINA FLUVIATILIS. 



THE COLOURED PLATES. 
PLATE XXII. (continued) 

MONOTOCARDIA. 
PTENOGLOSSA. 

IANTHINID.E. 

357. IANTHINA FRAGILIS. 

358. IANTHINA ROTUNDATA 

359. IANTHINA EXIGUA. 

SCALARIIDffi. 

360. SCALARIA TURTON/E. 

361. SCALARIA COMMUNIS. 

362. SCALARIA TREVELYANA. 

363. SCALARIA CLATHRATULA. 

364. SCALARIA PSEUDOSCALAKIS. 

365. ACLIS UNICA. 

366. ACLIS ASCARIS. 

367. ACLIS SUPRANITIDA. 
36$. ACLIS WALLERI. 

369. ACLIS GULSONVE. 

T&NIOGLOSSA. 

NATICIDJE. 

Plate XXIII. 370. NATICA ISLANDICA. 

371. NATICA GRCENLANDICA. 

372. NATICA SORDIDA. 

373. NATICA CATENA. 

374. NATICA ALDERI. 

375. NATICA MONTACUTI. 

376. NATICA AFFINIS. 

LAMELLARIID.E. 

377. LAMELLARIA PERSPICUA. 

378. VELUTINA PLICATILIS. 

379. VELUTINA L^VIGATA. 

TRICHOTROPID-ffi. 

380. TRICHOTROPIS BOREALIS. 

381. TORELLIA VESTITA. 

CAPULID.E. 

382. CAPULUS HUNGARICUS. 

383. CALYPTR^A CHINENSIS, 

384. CREPIDULA FORNICATA. 

HOMALOGYRID-E. 

385. HOMALOGYRA ATOMUS, 

386. HOMALOGYRA ROTA- 



1 THE COLOURED PLATES. 

PLATE XXIII. (continued) 

LITTORINIDJE. 

387. LITTORINA OBTUSATA. 

388. LITTORINA NERITOIDES. 

389. LITTORINA RUDIS. 

390. LITTORINA LITTOREA. 

391. LITTORINA ^STUARII. 

392. LACUNA CRASSIOR. 

393- LACUNA DIVARICATA. 

394- LACUNA TENELLA. 

395. LACUNA PUTEOLUS. 

396. LACUNA PALLIDULA. 

CYCLOSTOMATID^E. 

397- CYCLOSTOMA ELEGANS. 

ACICUI.ID.ffi. 

398. ACICULA LINEATA. 

TRUNCATELLIDJE. 

399. TRUNCATELLA TRUNCATULA. 

RISSOIDJE. 

Plate XXIV. 400. RISSOA STRIATULA. 

401. RISSOA LACTEA. 

402. RISSOA CANCELLATA. 

403. RISSOA CALATHUS. 

404. RISSOA RETICULATA. 

405. RISSOA CIMICOIDES. 

406. RISSOA JEFFREYSI. 

407. RISSOA PUNCTURA. 

408. RISSOA ABYSSICOLA. 

409. RISSOA ZETLANDICA. 

410. RISSOA COSTATA. 

411. RISSOA PARVA. 

412. RISSOA INCONSPICUA. 

413. RISSOA ALBELLA. 

414. RISSOA MEMBRANACEA. 
415- RISSOA VIOLACEA. 

416. RISSOA COSTULATA. 

417. RISSOA STRIATA. 

418. RISSOA PROXIMA. 

419. RISSOA VITREA. 

420. RISSOA PULCHERRIMA. 

421. RISSOA FULGIDA. 

422. RISSOA SOLUTA. 

423. RISSOA SEMISTRIATA. 

424. RISSOA CINGILLUS. 

425. BARLEEIA RUBRA. 



THE COLOURED PLATES. 
PLATE XXIV. (continued) 

HYDROBIIDJE. 

426. HYDROBIA ULV,E. 

427. HYDROBIA SIMILIS. 

428. HYDROBIA VENTROSA. 
429. HYDROBIA JENKINSII. 

430. BITHYNIA LEACHII. 

431. BITHYNIA TENTACULATA. 

ASSIMINEIDJE. 

432. ASSIMINEA GRAYANA. 

433- ASSIMINEA LITTORINA. 

SKENEIDJE. 

434- SKENEA PLANORBIS. 

JEFFREYSIIDJE. 

435- JEFFREYSIA DIAPHANA. 

436. JEFFREYSIA OPALINA. 

437. JEFFREYSIA GLOBULARIS. 

ADEORBID^. 

438- ADEORBIS SUB-CARINATUS. 

VIVIPARIDJE. 

439. VIVIPARUS CONTECTA. 

440. VIVIPARUS VIVIPARA. 

VALVATIDJE. 

441. VALVATA CRISTATA. 

442. VALVATA PISCINALIS. 

CERITHIIDJE. 

443. CERITHIUM METULA. 

444. CERITHIUM RETICULATUM. 

445. CERITHIUM PERVERSUM. 
446- CERITHIUM VULGATUM. 

447. CERITHIOPSIS TUBE.RCULARIS. 

448- CERITHIOPSIS BARLEEI. 

449. CERITHIOPSIS PULCHELLA. 

450. CERITHIOPSIS METAXA. 
451- CERITHIOPSIS COSTULATA. 

TURRITELLHXE. 
Plate XXV. 452. TURRITELLA TEREBRA. 

CJECIDJE. 

453. CAECUM TRACHEA. 

454. C^CUM GLABRUM. 

APORRHAIDiE. 

455- APORRHAIS PES-PELECANI. 
456. APORRHAIS MACANDRE^. 



l8 THE COLOURED PLATES. 

PLATE XXV. (continued) 

CYPRJEIDJE. 

457. CYPR/EA EUROP^A. 

458. OVULA PATULA. 

TRITONIDJE. 

459. TRITON NODIFERUS. 

460. TRITON CUTACEUS. 

GYMNOGLOSSA. 

EULIMID^. 

461. EULIMA POLITA. 

462. EULIMA INTERMEDIA. 

463. EULIMA DISTORTA. 

464. E-ULIMA STENOSTOMA. 

465. EULIMA SUliULATA. 

466. EULIMA BILINEATA. 

467. STILIFER TURTONI. 

PYRAMIDELLUXE. 

Plate XXVI. 468. ODOSTOMIA MINIMA. 

469. ODOSTOMIA NIVOSA. 

470. ODOSTOMIA TRUNCATULA. 

471. ODOSTOMIA CLAVULA. 

472. ODOSTOMIA LUKISI. 

473. ODOSTOMIA ALBELLA. 

474. ODOSTOMIA RISSOIDES. 

475. ODOSTOMIA PALLIDA. 

476. ODOSTOMIA CONOIDEA. 

477. ODOSTOMIA UMBILICARIS. 

478. ODOSTOMIA ACUTA. 

479. ODOSTOMIA CONSPICUA. 

480. ODOSTOMIA UNIDENTATA. 

481. ODOSTOMIA TURRITA. 

482. ODOSTOMIA PLICATA. 

483. ODOSTOMIA INSCULPTA. 

484. ODOSTOMIA DIAPHANA. 

485. ODOSTOMIA OBLIQUA. 

486. ODOSTOMIA WARRENI. 

487. ODOSTOMIA DOLIOFORMIS. 

488. ODOSTOMIA DECUSSATA. 

489. ODOSTOMIA CLATHRATA. 

490. ODOSTOMIA INDISTINCTA. 

491. ODOSTOMIA INTERSTINCTA. 

492. ODOSTOMIA SPIRALIS. 

493. ODOSTOMIA EXIMIA. 

494. ODOSTOMIA FENESTRATA. 
495- ODOSTOMIA EXCAVATA. 
496. ODOSTOMIA SCALARIS. 



THE COLOURED PLATES. 
PLATE XXVI. (continued) 

497. ODOSTOMIA RUFA. 

498. ODOSTOMIA LACTEA. 
499- ODOSTOMIA PUSILLA. 

500. ODOSTOMIA SCILL/E. 

501. ODOSTOMIA ACICULA. 

502. ODOSTOMIA NITIDISSIMA. 

RACHIGLOSSA. 
MURICID^. 

503. TROPHON MURICATUS. 

504. TROPHON BARVICENSIS. 

505. TROPHON TRUNCATUS. 

506. MUREX ERINACEUS. 

507. MUREX ACICULATUS. 

508. PURPURA LAPILLUS. 

509. PURPURA H^MASTOMIA. 

510. LACHESIS MINIMA. 

COLUMBELLID^. 

511. COLUMBELLA HALIyEETI. 

512. COLUMBELLA NANA. 

NASSIDJE. 

513. NASSA RETICULATA. 

514. NASSA NITIDA. 

515. NASSA INCRASSATA. 

516. NASSA PYGM/EA. 



Plata XXVII. 517- BUCCINUM UNDATUM. 

518. BUCCINUM HUMPHREYSIANUM 

519- BUCCINOPSIS DALEI. 

FASCIOLARIIDJE. 

520. FUSUS ANTIQUUS. 

Plate XXVIII. 521. FUSUS NORVEGICUS. 

522. FUSUS TURTONI. 

523. FUSUS ISLANDICUS. 

524. FUSUS GRACILIS. 

525. FUSUS PROPINQUUS. 

Plate xxix. 526. FUSUS JEFFREYSIANUS. 

527. FUSUS BERNICIENSIS. 

528. FUSUS FENESTRATUS. 



MARGINELLIDJE. 

529. MARGINELLA L^EVIS. 



2O THE COLOURED PLATES. 

PLATE XXIX. (continued) 

TOXOGLOSSA. 

CONIDJE. 

530. MANGILIA TERES. 

531. MANGILIA GRACILIS. 

532. MANGILIA LEUFROYI. 
533- MANGILIA LINEARIS. 

534. MANGILIA RETICULATA. 

535. MANGILIA PURPUREA. 

536. PLEUROTOMA STRIOLATA. 
537- PLEUROTOMA ATTENUATA. 
538. PLEUROTOMA COSTATA. 
539- PLEUROTOMA RUGULOSA. 
540. PLEUROTOMA BRACHYSTOMA. 
541- PLEUROTOMA GALERITA. 

542. PLEUROTOMA NEBULA. 

543. PLEUROTOMA L/EVIGATA. 
544- PLEUROTOMA N-rVALIS. 

545. PLEUROTOMA CARINATA. 

546. PLEUROTOMA SEPTANGULARIS. 

547. PLEUROTOMA RUFA. 

548. PLEUROTOMA TURRICULA. 

549. PLEUROTOMA TREVELYANA. 



OPISTHOBRANCHIATA. 

TECTIBRANCHIATA. 

BULLOIDEA. 

ACTJEONIDJE. 
Plate XXX. 550. ACTION TORNATILIS. 

TORNATINIDJE. 

551. TORNATINUS MAMMILLATUS. 

552. TORNATINUS TRUNCATULUS. 

553. TORNATINUS OBTUSUS. 

554. TORNATINUS VENTROSUS. 
555- TORNATINUS EXPANSUS. 
556. TORNATINUS HYALINUS. 
557- TORNATINUS GLOBOSUS. 

SCAPHANDRIDJE. 

558. SCAPHANDER LIGNARIUS. 

559- SCAPHANDER LIBRARIUS. 

560. CYLICHNA ACUMINATA. 

561. CYLICHNA NITIDULA. 

562. CYLICHNA UMBILICATA. 

563. CYLICHNA CYLINDRACEA, 

564. CYLICHNA ALBA, 



THE COLOURED PLATES. 21 

PLATE XXX. (continued) 

BULLION. 

565. BULLA HYDATIS. 

566. BULLA ELEGANS. 

567. BULLA UTRICULUS. 

568. ACERA BULLATA. 

PHILINID.S. 

569. PHILINE SCABRA. 

570. PHILINE CATENA. 
571- PHILINE ANGULATA. 
572. PHILINE QUADRATA. 
573- PHILINE PUNCTATA. 
574. PHILINE PRUINOSA. 
575- PHILINE NITIDA. 
576. PHILINE APERTA. 

APLYSIOIDEA. 

APLY8IIDJE. 

577- APLYSIA PUNCTATA. 

578. APLYSIA DEPILANS. 

579- ALPYSIA MELANOPUS. 

PLEUROBRANCHOIDEA . 

PLEUROBRANCHIDJE. 

580. PLEUROBRANCHUS MEMBRANACEUS. 

581. PLEUROBRANCHUS PLUMULA. 



582. RUNCINA HANCOCKI. 

PTEROPODA. 

THECOSOMATA. 

LIMACINIDJE. 

583. SPIRIALIS RETROVERSUS. 

CAVOLINIIDJE. 

584. CLIO PYRAMIDATA. 

GYMNOSOMATA. 

CLIONnXffi. 

585. CLIONE LIMACINA. 

ASCOGLOSSA. 

HERMJEHXE. 
Plate XXXI. HERM^EA BIFIDA. 

586. HERM^EA DENDRITICA. 

587. ALDERIA MODESTA. 



22 THE COLOURED PLATES. 

PLATE XXXI. (continued) 

ELYSIID^. 

588. ELYSIA VIRIDIS. 

LIMAPONTIID.S. 

589. LIMAPONTIA NIGRA. 
LIMAPONTIA DEPRESSA. 

590. ACT/EOXIA CORRUGATA. 
ACT^EONIA COCKSII. 



NUDIBRANCHIATA. 

CLADOHEPATICA. 

.ffiOLIDIDJE. 

ACOLIS PAPILLOSA. 
.EOLIS GLAUCA. 
^OLIS ALDERI. % 
591. ^EOLIS CORONATA. 

^iOLIS DRUMMONDI. 
/EOLIS PUNCTATA. 
/EOLIS ELEGANS. 

RUFIBRANCHIALI3. 

LINEATA. 

GRACILIS. 

JEOLIS SMARAGDINA. 
^EOLIS PELLUCIDA. 
/EOLIS LANDSBURGI. 
^OLIS ALBA. 
.EOLIS CARNEA. 

GLAUCOIDES. 

PEACHII. 
/EOLIS NANA. 

STIPATA. 

ANGULATA. 

I NORN ATA. 
.EOLIS CONCINNA 
;OLIS OLIVACEA. 

AURANTIACA. 

PUSTULATA. 

CONCHII. 

AMCENA. 

,OLIS NORTHUMBRICA. 
^iOLIS ARENICOLA. 
^EOLIS GLOTTENSIS. 

CCERUIxEA. 

VIRIDIS. 
^EOLIS PURPURASCENS. 

CINGULATA. 



THE COLOURED PLATES. 23 

PLATE XXXI. (continued) 

/EOLIS VITTATA. 
^OLIS PICTA. 
/EOLIS TRICOLOR. 
^EOLIS FARRANI. 

ADELAIDE. 

EXIGUA. 
JEOLIS DESPECTA. 
yEOLIS SANGUINEA. 
EMBLETONIA PULCHRA. 
592. EMBLETONIA MINUTA. 
EMBLETONIA PALLIDA. 
EMBLETONIA GRA.YI. 

593- FIONA NOBILIS. 

594- PROCTONOTUS MUCRONIFERUS. 

595- ANTIOPA CRISTATA. 
ANTIOPA HYALINA. 

596. HERO FORMOSA. 

LOMANOTIDJE. 

Plate XXXII. 597. LOMANOTUS MARMORATUS. 

LOMANOTUS FLAVIDUS. 

LOMANOTUS PORTLANDICUS. 

LOMANOTUS HANCOCKI. 

DOTONnXE. 

DOTO FRAGILIS. 

DOTO PINNATIFIDA. 

598. DOTO CORONATA. 
DOTO CUSPIDATA. 

DENDRONOTIDJE. 

599. DENDRONOTUS ARBORESCENS. 



600. SCYLL^A PELAGICA. 

PLEUROPHYLLIDIIDJE. 

601. PLEUROPHYLLIDIA LOVENI. 

TRITON IID.E. 

602. TRITONIA HOMBERGI. 
TRITONIA ALBA. 
TRITONIA PLEBEIA. 
TRITONIA LINEATA. 



24 THE COLOURED PLATES. 

HOLOHEPATICA. 

DORIDID^. 

Plate XXXIII. DORIS TUBERCULATA. 

DORIS FLAMMEA. 

DORIS ZETLANDICA. 

DORIS MILLEGRANA. 

DORIS TESTUDINARIA. 

DORIS JOHNSTONI. 

603. DORIS COCCINEA. 

DORIS REPANDA. 

DORIS ASPERA. 

DORIS PROXIMA. 

DORIS MURICATA. 

DORIS LOVENI. 

DORIS ULIDIANA. 

DORIS DIAPHANA. 

DORIS OBLONGA. 

DORIS BILAMET.LATA. 

DORIS DEPRESSA. 

DORIS INCONSPICUA. 

DORIS PUSILLA. 

DORIS SPARSA. 

DORIS PILOSA. 

DORIS QUADRANGULATA. 



POLYCERIDJE. 

604. POLYCERA QUADRILINEATA. 
POLYCERA OCELLATA. 
POLYCERA LESSONI. 

605. /EGIRUS PUNCTILUCENS. 

606. TRIOPA CLAVIGER. 

607. THECACERA PENNIGERA. 
THECACERA VIRESCENS. 
THECACERA CAPITATA. 

608. CRIMORA PAPILLATA. 



GONIODORIDJE. 

609. GONIODORIS NODOSA. 
GONIODORIS CASTANEA. 

610. ANCULA CRISTATA. 

611. IDALIA ELEGANS. 
IDALIA LEACHII. 
IDALIA ASPERSA. 
IDALIA IN/EQUALIS. 
IDALIA PULCHELLA. 
IDALIA QUADRICORNIS. 



CHAPTER III. 

CUTTLE FISHES, 



THE cephalopods or cuttles are the most specialised of molluscs. 
They form a class distinct from the others in structure and 
habits, and their shells, when present, are quite unlike those with 
which we have principally to deal. But they are undoubtedly 
mollusca, and, as such, demand attention before we are introduced 
to their humbler relatives. 

They are grouped into two orders : the Dibranchiata, which have 
two gills; and the Tetrabranchiata, which have four. The four-gilled 
division are not represented in British waters. The two-gilled 
cephalopods, which are represented by a dozen species, are 
divided into 

1. Octopoda having eight arms. 

2. Decapoda having ten arms. 

The Octopoda are divided into six families, one only of which is 
represented around our coasts, this being the Octopodidae, of which 
the two British genera are 

1. Octopus having two rows of suckers. 

2. Eledone having one row of suckers. 

The Decapoda are divided into thirteen families, of which three 
are recognised as British, these being 

1. Loliginidae having the shell narrow, pointed in front and as 

long as the back. 

2. Sepiolidae having the shell narrow and half as long as the body. 

3. Sepiidae having the shell with a thin chitinous margin, oval, 

thick in front, the posterior ventral end being concave and 
ending in a spine. 

The Loliginidae are represented by two genera : 

1. Loligo having the shell keeled on the ventral side, eyes with 

closed cornea. 

2. Ommastrephes having the shell ending in a hollow cone, eyes 

with open cornea. 

25 



26 



CUTTLE FISHES. 




BRITISH CUTTLE FISHES. 



CUTTLE FISHES. 




BRITISH CUTTLE FISHES. 



28 CUTTLE FISHES. 

Of these genera, Loligo has two species 

1. vulgaris having the head long. 

2. media having the head short. 

and Ommastrephes has also two species 

i todarus mouth with small suckers on the lip, shell blade smooth, 

loom with a mid-rib and two others. 
2. sagittatus no suckers near the mouth, shell blade striated 

longitudinally, loom with a mid-rib and more than two others. 

The Sepiolidae are represented by two genera : 

1. Rossia having the dorsal mantle free all round and supported 

by a ridge. 

2. Seplola having the dorsal mantle united to the head by a band. 

Of Rossia there are two species 

1. macrosoma having the head short and the eyes prominent. 

2. papilliftra having the head large and the eyes not prominent. 

Sepiola is represented by one species, rondektl, and the Sepiidae 
are represented by one genus, Sepia, of which there are three 
species 

1. officinaiis body broadly striped, fringe of shell broad at base. 

2. elegans body faintly striped, fringe of shell narrow at base. 

3. biserialis body lightly spotted, fringe of shell hooded at base. 
Arranging our list systematically, we have : 

CEPHALOPODA. 

DIBRANCHIATA. 

OCTOPODA . 
OCTOPODIDJE. 

I. Octopus vulgaris. 
II. Eledone cirrosa. 

DEC A POD A . 
LOLIGINIDvE. 

III. Loligo vulgaris. 

IV. Loligo media. 

V. Ommastrephes todarus. 
VI. Ommastrephes sagittatus. 
SEPIOLIDJE. 

VII. Rossia macrosoma. 
VIII. Rossia papillifera. 
IX. Sepiola rondeleti. 

8EPIIDJE. 

X. Sepia officinaiis. 
XI. Sepia elegans. 
XII. Sepia biserialis. 



CUTTLE FISHES. 2Q 

In the accompanying illustrations, on pages 26 and 27, every 
British species is figured except Rossia papillifera, which derives 
its name from the crowd of small, whitish pimples with which it 
is covered on the back of the mantle, the head, and the arm. This 
species differs from macrosoma not only in the proportionate size 
of the head, but in the greater stoutness of the body, and it is 
almost the smallest of the British cuttles. Its length is about an 
inch and three-quarters, that of Sepiola rondeleti being an inch and 
a half or less. Rossia macrosoma, like Sepia biserialis, is three inches 
long; Sepia elegans measuring four inches, and Loligo media five. 
Octopus and Eledone may be averaged at six inches, and Loligo 
vulgar Is at two feet, the other three species rarely exceeding a foot. 



CHAPTER IV. 



MULTIVALYES AND BIVALVES, 



FOR the purposes of identification, the other mollusca may be 
divided into multivalves, bivalves, and univalves. This is, 
perhaps, a little too suggestive of classifying the races of mankind 
according to the clothes they wear, and the more so as many of the 
mollusca, like many of the men, never or hardly ever wear any 
clothes at all. But as we are dealing with shells, and most of us 
are more likely to become acquainted with the shell than with the 
wearer, it is advisable to begin in this way. 

First, then, for the multivalvular -s^hell ; and it will not detain us 
long, as there is only one genus accepted as British which has a 
shell of the kind. That genus is Chiton, and its species can be 
recognised at once by the resemblance they bear to the ordinary 
woodlouse or garden armadillo. 

In appearance the Chitons differ from any other mollusca, and it 
is at first sight difficult to believe that they belong to the sub-kingdom, 
or that they can be grouped with the Gastropoda as they now are. 
The shell is built up of eight plates, which overlap from behind 
forward, like the tiles of a house, so that the animal, when alarmed, 
can roll itself up into a ball. A head-piece of the shape A, a tail- 
piece of the shape C, and half-a-dozen plates of the shape B, are 
held together by a muscular girdle so as to form the shape D : which 
is distinctive enough to be left to speak for itself. 



B 




THE PARTS OF A MULTIVALVE SHELL (Chiton discrepant}. 

Having got rid of these unexpected forms, we can give our 
attention to the bivalves and univalves, taking the oivalves first, as 
being more easily dealt with, and less in number. 

30 



MULTIVALVES AND BIVALVES. 



Sinus'" 



..-Aoherior 

muscle acar 




,. Pallia! line 



marqm 





AnVerior margin 

THE PARTS OF A BIVALVE SHELL (Mactra glauca). 



32 MULTiVALVES AND BIVALVES. 

At the outset let us have a diagram to illustrate the few terms 
we shall have to use. Here is one valve of a shell. At the top is the 
umbo or beak, which in this instance is not in the middle of the 
upper edge, but a little to the side to which it points. That side is 
the anterior side. Beaks almost always point forwards, and the 
animal's mouth is always at the fore end, the siphons, when they 
are present, being at the posterior end. Roughly parallel to the 
lower edge of the shell is the pallial line, which is the muscular edge 



Posterior pedal redact-on 



An her! or pedal refractor 




adductor 



Posterior &dducl-or 



Pedal prohracf-or 

LEFT VALVE OF Unio pictorum. 



of the so-called mantle which secretes the shell ; the sinus, or 
indentation, caused by the muscles which retract the siphons, 
breaks into the pallial line, and is always on the posterior side ; and 
the longer the siphons the larger the mark. When the siphons are 
not retractile, there is no sinus. Siphons are the muscular tubes 
formed by the extension of the mantle, one of them being branchial 
and inhalent, and the other exhalent : so that there is a steady 
current of water down the branchial tube and up the other one. 

At each end of the pallial line is a scar ; these are the marks 
made by the adductor muscles which close the shell. When there 
is but one muscle it is always the posterior, and is consequently 
nearer that side than the other. These are not the only scars in 
every shell. In the third diagram we have one of the Unionidae, 
in which it will be seen that above the posterior adductor, and 
apparently in continuation of it, is the mark of the posterior pedal 
retractor muscle which draws in the animal's foot. Adjoining the 
anterior adductor is the corresponding anterior pedal retractor, and 
below it is the pedal protractor, which protrudes the foot. 

The ligament opens the shell, and is, as a rule, behind the beaks, 
the depression around it outside, when there is one, being the 
lozenge, or escutcheon, the area in front of the beaks being the 
lunule. When the hinge line is unusually long, the ligament extends 



MULTIVALVES AND BIVALVES. 



33 



on both sides of the beak. It may be wholly external or internal, 
or partly one and partly the other; when it is external, the 
edges of the shell are cut away to receive it, when it is internal, 
it fits into a sort of pit known as the fossette. Really it is made up 
of the ligament proper outside and the cartilage within, which are 
generally continuous ; but in some cases, as in our example, which, 
by the bye, is a species of Mactra, the cartilage is quite separate, 
and is in a pit within the hinge. 

The hinge is the most important part of the shell, but, before we 
consider it, let us put both valves together, so as to be clear with 
regard to a few more terms. Looking down on the back of the 
shell we see the beaks pointing forwards over the lunule ; the 
anterior end is thus away from us, the posterior towards us. The 
valve to our left when in this position is the left valve, the other 
the right valve. The upper part of the shell, where the beaks are, is 
the dorsal margin, opposite to it is the ventral margin, the other 
margins being anterior and posterior, or fore and hind, as they are 
often termed. The length of the shell is, in this book, taken as being 
between the extreme points of the fore and hind margins; the 
breadth being between the ventral and dorsal margins. Along the 
dorsal margin is the hinge area. 

The hinge most frequently bears a series of prominences and 
indentations interlocking with each other, and known as teeth. 
Immediately beneath the beak are the hinge-teeth proper, the 
" cardinals " (from cardo, the Latin for hinge), and on each side of 
the cardinals, and extending some distance from them, are the 
" laterals," the cardinals being, as a rule, compact and pointed, while 
the laterals are narrow and thin. These teeth are so invariable in 
their number and arrangement in different genera that they can be 
used as guides in classification, and can be stated in the terms of a 
dental formula, in which the middle term stands for the cardinal. 
Thus i, 2, i, means that the hinge has two cardinal teeth with a 
single lateral on each side of them. There is almost every variety 
of hinge, from that with strong prominent teeth, to a mere series of 
serrations all alike, and even to no teeth at all. 

One group of bivalves, the Pholadacea, have no teeth and no 
hinge, and, at the most, but a very rudimentary ligament. They 
are so different from the rest that we may as well sort them out 
first. They can be recognised by the dorsal plates on the back of 
the junction of the valves, and by the apophyses or falciform pro- 
cesses within the shell to which some of the muscles are attached. In 
British representatives of the sub-order the genera with long 
apophyses are the borers Pholas and Pholadidea, the latter being 
easily distinguished by the shell not being prickly all over, arid by 
its having a sort of horny cup at its posterior end. 

The only native genus with short apophyses is Xylophaga. In 
the same sub-order is now included the genus Teredo, of evil 
reputation as a borer of wood. Its shell, which is difficult to 
understand until it is seen in place on the animal, is continued into 
a calcareous tube with long siphons, near the end of which, and 
acting as valves, are a pair of pallets not unlike the scales of a 
gigantic butterfly. No one is likely to mistake a Teredo for any 
other mollusc. 



34 MULTIVALVES AND BIVALVES. 

The bivalves used to be classified on the pallial line ; it was not 
a perfect system in some ways, but it comes in excellently as a 
guide in dealing with the shells only, and, with a few qualifications 
of the free and easy sort, we will adopt it here. It is possible to 
divide the group into those with the pallial line indented and those 
with it entire, but those without the indentation are so numerous 
that the table is too long to work with readily. Hence we will keep 
to the old lines, and, as shown in the alphabetical list of British 
genera herewith, have three categories: 

A. Those having the pallial line not indented and having 

no siphons. 

B. Those having the pallial line not indented and having 

short siphons. 

C. Those having the pallial line indented and having long 

siphons. 

In the C division everything is straightforward. With regard to 
A, all that can be done is to run through it, and if the genus cannot 
be discovered, to pass on to B, which is not so difficult after all, and 
will be found to be much more exp'aditious than with any com- 
bination of the two. We say genus, for the British bivalves are com- 
paratively so few that we can afford to disregard orders, sub-orders, 
and families, and deal with the genera direct, which is more satis- 
factory, as they are least likely to be affected by changes in 
classification. 

Let us look, then, if our shell's pallial line be indented or not, and 
if it be, we will assume that the animal had no siphons. We will 
then ask if the valves are of the same size, or is one larger than the 
other? Is it 

1. Inequivalve, or 

2. Equivalve ? 

Supposing it be inequivalve, is it equilateral, or nearly so ? That is, 
does a straight line dropped perpendicularly from the beak to the 
ventral margin divide the surface of the valve into halves ? If it 
does, has the shell any ears that is, winged processes on the side 
of the beak ? If it has ears, the shell is a Pecten ; if it has none, it 
is either Anomia or Ostrea : the former if it has the hole in its lower 
valve through which passes the byssus by which it is fastened to the 
rock, the latter if it has no hole. Here we have: 

Equilateral, or nearly so 
With ears Pecten. 
Without ears 

With hole Anomia. 
Without hole Ostrea. 

If the shell is markedly inequilateral, we can further advance to : 

Very oblique 

With teeth Avlcula. 
Without teeth Pinna. 

Neither of these is like anything else : in fact, the five genera thus 
chosen are easy ones to begin with. 



MULTIVALVES AND BIVALVES. 


Pallial line not indented 


No siphons 


Short siphons 


Anodonta. 


Astarte. 


Anomia. 


Cardium. 


Area. 


Circe. 


Avicula. 


Cyamium. 


Axinus. 


Cyprina. 


Crenella. 


Diplodonta. 


Dreissensia. 


Galeomma. 


Leda. 


Isocardia. 


Lima. 


Kellia. 


Limopsis. 


Lasaea. 


Modiolaria. 


Lepton. 


Mytilus. 


Loripes. 


Nucula. 


Lucina. 


Ostrea. 


Montacuta. 


Pecten. 


Pisidium. 


Pectunculus. 


Sphaerium. 


Pinna. 




Unio. 





35 



Pallial line indented 



Long siphons 
Amphidesma. 
Ceratisolen. 
Corbula. 
Donax. 
Gastrana. 
Gastrochcena. 
Lucinopsis. 
Lutraria. 
Lyonsia. 
Mactra. 
Mya. 
Neasra. 
Pandora. 
Panopaea. 
Petricola. 



Long siphons 
Pholadidea. 
Pholas. 
Poromya. 
Psammobia. 
Saxicava. 
Scrobicularia. 
Solecurtus. 
Solen. 
Tapes. 
Tellina. 
Teredo. 
Thracia. 
Venerupis. 
Venus. 
Xylophaga. 



36 MULTIVALVES AND BIVALVES. 

Now let us deal with those in which the valves are of equal size. 
These we can divide into those with ears and those without ; and 
those with ears we can then subdivide into that with teeth, which is 
Limopsis, and that without, which is Lima, the latter being further 
distinguished by having one muscular scar while the former has two. 
We thus get : 

Shell equivalve 
With ears 

With teeth Limopsis. 
Without teeth Lima. 

We can continue this : 

Without ears 

Hinge with many teeth 
Hinge straight Area. 
Hinge curved 

Shell round Pectunculus* 
Shell elongated Leda. 
Shell trigonal Nycula. 

Here Area, with its long, straight row of teeth all alike, is un- 
mistakable ; Pectunculus has its teeth in two groups, one on each 
side of the beak, and affords the first instance of the evolution of the 
forms of teeth ; in Leda the shell is lengthened out at the posterior 
end so as to give it a somewhat leg-of-mutton appearance, and the 
teeth on each side of the beak are nearly equal in number ; in 
Nucnla, which has a shell like a nut, the teeth are much more 
numerous on the posterior side than on the other. 

The next group can include those having few or no teeth, and 
one of them, Axinus, can be picked out at once, owing to its shell 
being almost circular. That leaves us with the rest inequilateral, 
which we can separate into those with the ligament external and 
those with it internal. The former we can further sort into : 

Teeth conspicuous Unio. 
Teeth inconspicuous Anodonta. 

Those with an internal ligament are only four in number : 

Crenella, which has radial ribs and one upright tooth, the hinge 
margin being crenulaied behind the ligament. 

Modiolaria, which has two groups of striations, one down each 
margin. 

Dreissensia (the fresh-water mussel), which is very oblique, and 
has the beaks terminal and pointed and has a shelf within 
the beak. 

Mytilus (the salt-water mussel), which is of similar shape but 
has no shelf. 

If our specimen is not one of these, and they are all distinct in 
form, we must proceed to the genera in which the pallial line is not 



MULTIVALVES AND BIVALVES. , 37 

indented and the animal is not siphonless, though the siphons are 
not very long. Of these there are only sixteen, one of which 
Cardiumha.s bold radial ribs; one Isocardia has twisted beaks ; 
and one Lepton is oblong with almost square corners. Let us put 
this into form : 

Grooves radial Cardium. 
Grooves concentric 

Beaks twisted Isocardia. 
Beaks not twisted 

Hinge without teeth Galeomma. 
Hinge with teeth 

Shell oblong Lepton. 
Shell triangular 

Two teeth in each valve A start e. 
Three teeth in each valve Circe. 

Here, Astarte the more important genus can be further dis- 
tinguished by its having all the teeth entire, while Circe has one tooth 
cloven, so as to make the three look like four. We can continue 
this table : 

Shell circular or sub-orbicular 
Ligament internal 

Anterior scar long and extending within pallial line 

Loripes. 

Anterior scar orbicular Montacitta. 
Anterior scar oval 

Left cardinal small Lasaa. 

Left cardinal thick and erect Kellia. 

In this group Montacuta is at once distinguishable from Loripes 
by its much smaller size, and Lascza from Kellia by its reddish 
colour. Our next genus had better be Diplodonta, of which our only 
representative is a beautiful little shell, white and almost trans- 
parent, equivalve and almost circular, with a double ligament more 
or less external and with two teeth in each valve, the anterior in the 
left and posterior in the right being bifid. Next to it we will place 
Cyamium, the smallest of our bivalves, which can only be examined 
under the microscope, and is recognisable at once by its ligament 
rising conspicuously above the level of its dorsal line. There are 
two other genera in which the ligament is obtrusively apparent, 
though it is partially overlapped in a groove. These are Lucina, 
which has the anterior scar narrow and projecting a long way within 
the pallial line ; and Cyprina, in its solitary species, one of the 
finest of British shells, thick, large, and heavy, in which the muscular 
scars are so oval and shiny as to be characteristic, though it is 
hardly worth while to look inside when the outside is so unmistakable. 

We have nearly finished with Division B. Only two genera 
remain, and these used to be one. In them the ligament is incon- 
spicuous, and the shell horny and translucent. One of them, 
Spharium, has the beak almost midway ; the other, Pisidium, has 
the beak near the anterior end. Both of them are freshwater. 
They are the only British representatives of the Cyraeriidae. 



38 MULTIVALVES AND BIVALVES. 

Our third division includes all those bivalves in which the 
pallial line is indented by the impression caused by the insertion of 
the siphon's retractor muscle. The impression shows that the 
siphons are long compared to the length of the shell, and the siphons 
are long because the animal lives buried in the sand and has to 
thrust these tubes up into the water to be able to breathe. As we 
have said before, one of these siphons is exhalent, the other inhalent. 
The inhalent, or branchial siphon, is that near the ventral margin ; 
the upper one, nearer the beak, is the anal. In the numerous cases 
in which they end differently, the one that bears the tentacles, or 
more tentacles than the other, is the branchial siphon. 

This group of genera can be divided into those with one valve 
larger than another and those with equal valves ; and those with 
equal valves can be further divided according to the way in which 
they gape. In this way, we get two groups of three each : 

Shell inequivalve 
Nearly equilateral. 
Elongated at posterior end. 
Truncated at posterior end. 

% 

Shell equivalve 

Gaping at both ends. 
Gaping at posterior end. 
Gaping at neither end. 

In the first triad there are only four genera. Lyonsia is nearly 
equilateral, and any doubt concerning it can be set at rest by a look 
at the ligament, which is in an internal groove. Pandora is elongated 
at the hinder end. Thracia and Corbula are both truncated at the 
hinder end, but Thracia is much larger than the other, and has a 
crescentic ossicle in its cartilage pit ; while Corbula has no ossicle, 
and fixes its cartilage in a cavity of its solitary cardinal. In appear- 
ance the only native species of Corbula is more like a brachiopod 
than any other bivalve. 

The equivalve shells that gape at both ends can also be divided 
into three categories. Of the first the sole representative is Mya, 
which has a broad shell with a broad, short shelf, not unlike the 
scale of a fish. Of the second the only representative is Lutraria ; 
its shell is oblong, and very oblique. The third is made up of the 
Solenidae, and is as follows : 

Shell long and narrow 

Hinge nearly midway, with radiating ribs Ceratisolen. 
Hinge terminal with one cardinal in the right valve Solen. 
Hinge sub-terminal with two cardinals in the right valve 
Solecurtus. 

Ten genera are represented in the group having the shell gaping 
at the posterior end. Two of them have the cartilage in a triangular 
cavity under each beak, these being Poromya, which has an oval 
shell, and Neczra, in which the hinder end is lengthened out into a 
sort of stalk. Two of them have the shell cut off short at the hinder 
end, these being Panopaa, which has the pallial line continuous, and 



MULTIVALVES AND BIVALVES. 39 

Saxicava, in which it is broken up. One genus, Scrobicularia, has 
the beaks turned away from the fore end ; another, which has a 
wrinkled periostracum extending over the siphons, is in this group 
only as regards one of its species, Mya binghami. One shell, Castro- 
chana dubia, has a long, calcareous sheath ; one, Petricola, is long 
and thin and prickly, and looks like a narrow Pholas ; one, Venerupis, 
is decorated with concentric rows of plates almost as thin as paper ; 
and the tenth, Psammobia, is striated concentrically, and also (more 
or less faintly) radially, particularly at one end in the case of two of 
the species, ferroensis and costulata, besides being distinguishable by 
its flat, narrow shape, and its beautiful rays of subdued pinks and 
purples. 

Nothing would be gained by here tabulating this rather mis- 
cellaneous lot, and we can proceed to our last group in which the 
shell does not gape at either end. These we can divide into those 
having the ligament partly external and partly internal and those in 
which it is wholly external. Thus : 

Ligament partly external 

Teeth unequal in both valves Mactra. 

Teeth unequal in right valve only A mphidesma. 

Concerning which it may be worth noting that one only Amphi- 
desma is reddish brown, while all the species of Mactra are white or 
pale stone colour. We are left with those shells in which the 
ligament is entirely external, and these can be sorted out into : 

Teeth two in right valve 

Inside margins notched Donax. 
Inside margins not notched 

Shell with a white ray Donax politus. 
Teeth in left valve unequal Gastrana. 
Teeth in left valve equal 

Shell as broad as long Lucinopsis. 
Shell not so broad as long Tellina. 

Teeth three in both valves 

Sinus rounded Tapes. 
Sinus angular Venus. 

Here the only difficulty is with Donax, two species of which have 
toothed edges, while the other has the edges smooth but is at a 
glance recognisable by the white ray extending from the beak to the 
ventral margin. Another Donax, trunculus, can be picked out at 
once by the curious manner in which it is cut off short, making it 
look like half a shell, so that among the bivalves it is what the 
sunfish is among fishes. Both Gastrana and Lucinopsis are thin and 
fragile; and of the last pair Tapes can be distinguished from Venus 
by its being more oval and oblique, its only species approaching to 
a roundish form being decussatus, which can be identified among the 
crowd by the bold and numerous radiating striae which seem to 
ripple from its beaks. 

Hitherto we have been dealing with the shells ; let us now direct 
our attention to those who live in them. Let us leave conchology, 



4 o 



MULTIVALVES AND BIVALVES. 



the study of the shell, for malacology, the study of the mollusc. 
The animal of Tapes decussatus has long been a favourite article 
of food on the continent. It is oval and white, and the margins 
of its mantle have a scalloped fringe. The siphons are equal, and 
separate all the way up, and they are of a yellowish tint, dotted 
towards the base and middle and speckled towards the end with 
light brown. The orifice of the inhalent siphon has a double border 
of a dozen long cirrhi alternated with a dozen that are not so long, 
but the exhalent siphon has some twenty simple cirrhi, which, like 
the others, are brown. The foot has a byssal groove, and is large, 
white, and lanceolate, and, like the other parts, well-marked ; in 
fact, the species is an excellent one for dissection. Let us, however, 
as our example, take a better known edible bivalve, the common 
oyster, which everyone can get and experiment upon. 



Beak 



Culler 




M&nfle 



PARTS OF AN OYSTER (Ostrea edulis). 



Here we have an oyster with the flat or left valve removed. At 
the top is the beak, and near it is the ligament which opens the 
valves, and almost in the centre is the adductor which closes the 
valves, and which being cut through close to the shell by the expert 
opener, allowed of the left valve being pulled up by the ligament, as 
if the animal were dead and the muscular power had been lost. 



MULTIVALVES AND BIVALVES. 4! 

There is but one adductor ; the anterior, as in the pectens, having 
become atrophied owing to the shape of the shell bringing the 
hinge and two adductors into line. To make up for this, the 
surviving adductor, the posterior, having more to do, becomes of 
conspicuous size. 

Above the adductor, on the median line, is the heart, with its 
single ventricle and two auricles, pulsating in the pericardium as it 
drives the colourless blood through the system. Below the ligament 
is the mouth, with its palps, leading down into the gullet and the 
stomach, and onwards to the intestine. Round the loop of the 
intestine is the greenish-brown liver, from which the tubes lead into 
the stomach and carry into it the digestive fluid. 

On the anterior side the gills start from the palps and curve half- 
way round. The gills are the " beard," which everyone does not 
appreciate as an article of food, and is often thrown away by the 
opener. There are two gills, each consisting of two thin plates, flat, 
but diminishing in thickness towards the outer edge. The blood is 
brought through the arteries to a venous canal, and thence thfough 
the renal organ to the gills, whence, after being aerated, it returns 
by a canal on each side to the two auricles, or rather the one auricle 
which is in two divisions. Outside the gills, and extending all 
round, is the mantle, which encloses the body, and is protected by 
the shell it secretes. 

The oyster has no foot and no siphons, but its general body 
structure may be taken as representing that of the rest of the class. 
One family, however, is so unlike the others that some explanation 
is necessary. The family contains the one genus, Teredo, the ship- 
worms. The shipworm is a worm in appearance, with a pair of 
valves protecting one end and a pair of pallets protecting the other. 
The animal, so far as its principal organs are concerned, is very small, 
and is contained within the nut-like pair of valves that are without 
either hinge or ligament. The siphons, into which the gills are pro- 
longed, occupy eleven-twelfths of the length. These siphons secrete 
a shelly lining as the animal burrows its way into the wood, and at 
their point of separation are placed the calcareous pallets which 
close the tube against intruders. The larger of the siphons takes 
in the water charged with air and food, and down the smaller tube 
is ejected the spent water and the woody pulp formed as the animal 
bores deeper and deeper out of its own danger to the danger of the 
unsuspecting mariner. 

Our species of Teredo are all easily distinguishable by their 
pallets, those of bipinnata being, as figured on the coloured plate, of 
most characteristic structure. They are five times the length of the 
valves, their blades being composed of about fifty conical joints 
nested one within another, having feathered edges fringed on each 
side. The stalk, instead of being short, as in the other species, is 
long and slender and minutely tuberculated. It may be added that 
in the plate there are shown a single valve and pallet of each species, 
with a figure of the tube in the case of No. 167. 

One more note. Brachiopods have shells not unlike those of 
pelecypods, and are frequently listed with the British mollusca. 
What a brachiopod may be is rather a puzzle, but it is certainly not 
a mollusc ; arid it ought therefore to be out of our range. As, 



42 MULTIVALVES AND BIVALVES. 

however, only eleven species are claimed as British, we may as 
well give the list : 

TESTICARDINES 
Terebratulid ae 

Terebratulina caput serpentis. 
Terebratula capsula. 
Waldheimia cranium. 
Waldheimia septigera. 
Terebratella spitzbergenensis. 
Argiope decollata. 
Cistella cistellula. 

Rhynconellidae 

Atretia gnomon. 
Rhynconella psittacea. 

ECARDINES 

Craniidae^- 

Crania anomala. 

Discinidas 

Discinisca atlantica. 

For the purposes of identification we can tabulate these genera 
as follows : 

Shell without hinge 

Foramen in ventral valve Discinisca. 
No foramen Crania. 

Shell with hinge- 
Loop reflected 

Loop attached to septum Terebratella. 
Loop not attached to septum 

Shell smooth 

Loop small Terebratula. 

Loop large Waldheimia (as regards cranium}. 

Shell striated Terebratulina. 

Shell ribbed Waldheimia (as regards septigera). 

Loop not reflected- 
Shell semi-ovate and ribbed Argiope. 
Shell without ribs or striations Cistella. 

No loop, but short, curved crura 
Foramen beneath beak 
Black in colour Rhynconella. 
Not black in colour Atretia. 

As for our own convenience we arranged our illustrations in a 
way peculiar to ourselves, it is desirable that we should here give in 



MULTIVALVES AND BIVALVES. 43 

brief one of the systematic schemes that has much to recommend it, 
mentioning only such families as are represented in the British 
fauna so far as at present known. 

I. CEPHALOPODA. 

i. Dibranchiata. 

1. Octopoda. 

Octopodidae. 

2. Decapoda. 

1. Phragmophora. 

Spiruhdae (drifted specimens only). 

2. Se<piophora. 

Sepiidae. 

3. Chondrophora. 

Sepiolidas. 

Loliginidae. 

Ommastrephidse. 

ii. Tetrabranchiata (none). 

II. GASTROPODA, 
i. Amphineura. 

1. Polyplacophora. 

Lophyroidea. 

2. Aplacophora (none). 

ii. Prosobranchiata. 

1. Diotocardia. 

1. Docoglossa. 

Acmasidae. 
Lepetidse. 
Patellidae. 

2. Rhipidoglossa. 

Zygobranchiata. 

Fissurellidae. 

Haliotidae. 

Plejirotomariidae, 
Azygobranchiata. 

Cyclostrematidae. 

Trochidas. 

Turbinidae. 

Neritidae. 

2. Monotocardia. 

i. Ptenoglossa. 
lanthinidae. 
Scalariidse. 



44 



MULTIVALVES AND BIVALVES. 

2. Taenioglossa. 
Platypoda. 
Naticidae. 
Lamellariidse. 
Trichotropidse. 
Capnlidae. 
Homalogyridse, 
Littorinidae. 
Cyclostomatidae. 
Aciculidae. 
Truncatellidas. 
Rissoidas. 
HydrobiidaG. 
Assimineidae. 
Skeneidae. 
Jeffrey slid aj. 
Adeorbidae. 
Viviparidae. 
Valvatidae. 
Ceritijiidae. 
Turritellidas. 
Caecidae. 
Aporrhaidae, 
Cypraeidae. 
Tritonidae. 
Heteropoda (none). 

3. Gymnoglossa. 

Eulimidae. 
Pyramidellidae. 

4. Rachiglossa. 

Muricidae. 

Colnmbellidas. 

Nassidae. 

Buccinidas. 

Fasciolariidas. 

Marginellidas. 

5. Toxoglossa. 
Conidae. 

iii. Opisthobranchiata. 
i. Tectibranchiata. 

1. Bulloidea. 

Actaeonidae. 

Tornatinidas. 

Scaphandridas. 

Bullidas. 

Philinidae. 

2. Aplysioidea. 

Aplysiidae. 



MULTIVALVES AND BIVALVES. 45 

3. Pleurobranchoidea. 

Pleurobranchidas. 
Runcinidae. 

4. Siphonarioidas (none). 

2. Pteropoda. 

1. Thecosomata. 

Limacinidas, 
Cavoliniidae. 

2. Gymnosomata, 

Clionidae. 

3. Ascoglossa. 

Hermasidae. 

Elysiidae. 

Limapontiidae. 

4. Nudibranchiata. 

1. Cladohepatica. 

^Eolididae. 

Lomanotidaa. 

Dotonidae. 

Dendronotidae. 

Scyllaeidae. 

Pleurophyllidiida. 

Triton iidae. 

2. Holohepatica. 

Dorididae. 

Polyceridae. 

Goniodoridae. 

iv. Pulmonata. 

1. Basomrnatophora. 

Auriculidae. 
Otinidae. 
Limnaeidae. 
Physidae. 

2. Stylommatophora. 

Testacellids. 

Limacidae. 

Helicidse. 

Pupidae. 

Stenogyridra. 

Succineid;e. 

Onchidiidae. 

III. SCAPHOPODA, 

Dentaliidae. 

IV. PELECYPODA. 

i. Protobranchiata, 
Nuculidae. 



46 MULTIVALVES AND BIVALVES, 

ii. Filibranchiata. 

1. Anomiacea. 

Anomiidae. 

2. Arcacea. 

Arcadae. 

3. Mytilacea. 

Mytilidae. 

iii. Pseudolamellibranchiata. 
Aviculidae. 
Ostreidae. 
Pectinidae. 
Limidae. 

iv. Eulamellibranchiata. 

1. Submytilacea. 

Carditidae. 

Astartidae. 

Cyprinidae. 

Unionidae. * 

Dreissensiidae. 

Lucinidae. 

Erycinidae. 

Galeommidse. 

Cyraenidae. 

2. Tellinacea. 

Tellinidae. 
Scrobiculariidas. 
Donacidae. 
Mactridae. 

3. Veneracea. 

Veneridae. 
Petricolidae. 

4. Cardiacea. 

Cardiidae. 

5. Myacea. 

Psammobiidae. 

Myidae. 

Solenidas. 

Glycimeridae. 

Gastrochoenidse, 

6. Pholadacea. 

Pholadidae. 
Teredinidae. 

7. Anatinacea. 

Pandoridae. 
Lyonsiidae. 
Anatinidae. 

v. Septibranchiata. 
Poromyidae. 



CHAPTER V. 

UNIVALVES, 



LIKE all things else the mollusca are more interesting the more 
we know of them. They are far from being the mere masses 
of flesh or jelly they may seem at first sight. Their structure is 
anything but simple ; their organs are well defined ; their senses are 
in full complement. 

They can see. The Razor-shell will pop down into its hole at 
your near approach ; the Oyster will snap its valves as the shadow 
of your boat goes over it; and Cydostoma will shut itself in with 
its operculum if you hold a stick within a foot of it. The old 
rhyme of beating the snail is not so meaningless as it appears, 
but the snail will retire into its shell instead of coming out of it if 
the stick be held within its range of vision, which has been found 
to be two inches, the Helicidse being among the most short-sighted 
of their class. To say nothing of the great orbs, fifteen inches 
across, of the giant cuttle, it is difficult to forget the range of gems 
along the mantle edges of the Pecten, who requires a good look-out 
as he drives himself along, hydraulically, by clapping his valves 
together and squirting the water from each side of his hinge. 

They can hear. The Swan Mussel will shut its shell at the 
sound of a whistle or of a creaking door, and Anomia will close up 
as soon as you favour it with a musical note of a certain pitch. Yet 
the ears are not external, and in only one family, the Nuculidse, has 
a free communication been discovered between the otocyst (that is, 
the organ of hearing), and the exterior. 

They can smell. All the whelks in the neighbourhood will gather 
round a lobster pot ; hang a piece of meat over sand in which a 
Nassa is buried, and he will come up in a hurry to see what he can 
get ; a Helix will come a hundred yards after a strawberry, and 
retreat fifty from a whiff of turpentine; an Arion has been seen 
making for a bean-pod in a road, the pod has been picked up and 
the Arion has stopped and gone round and round waving his 
tentacles; the pod has been placed on the road again and the Arion 
has made straight for it, and again it has been shifted, so that the 
unfortunate slug has been led backwards and forwards at will. 

They can feel. Nothing is more noticeable than the varied forms 
of their organs of touch the tentacles, palps, mantle-lobes, arms, 
and crowns, which are found amongst them. They can taste, and 
are particular in their choice of food, except in respect of the few 
that are omnivorous. And some of them, when hungry, are un- 
expectedly bold in their choice of prey, as Limnaa peregra in 
feeding on minnows, and Limncea stagnalis in choosing newts and 

47 



48 UNIVALVES, 

sticklebacks ; and some are cannibalistic, or nearly so, as Helix 
pisana or Helix ericetorum. 

They have the sense of locality. Allowing for his limited means 
of locomotion, a snail is as good a homer as a pigeon. He will go 
out every evening and be found at home again every morning ; and, 
what is more, he can find food over a garden wall and return to tell 
his mate and take her back with him to have a meal, and then escort 
her home again ; and for months he has been known to live in the 
same crevice, from which, in one case at least, he has been taught 
to come out and show himself when spoken to. And it is not only 
the land species that go foraging, even the limpet will go for a cruise 
as soon as the rising tide covers it, and returns to its pit before the 
ebb has left it dry again. 

Slow as a snail may be, he is not weak. He can drag vertically 
nine times his own weight, and there is one experiment of Sandford's 
in which a specimen weighing a third of an ounce dragged along a 
smooth table twelve reels of cotton, a pair of scissors, a screw- 
driver, a key, and a knife, all tied on one behind the other, the 
weight of the load being seventeen ounces, or more than fifty times 
the weight of the drawer, the proportion being the same as if a 
twelve-stone man were to pull along 3 tons 15 cwt. 

The strength of a mollusc lies in its so-called foot, an organ which 
has been described as a thickening of a portion of the integument, 
modified to give different forms of motion. In some cases the motion 
occurs only during infancy, and is very slight ; in others it lasts 
through life, and is of even a violent character, as in the case of 
the cockles, which move in a succession of long hops. Some, like 
Natica, use the foot -as a sand plough ; some, as the Tectibranchs, 
as a fin to swim with ; some, as Mya, as a spade to dig with ; some, 
as Pholas, as a drill to bore with. Sometimes it is comparatively 
large, as in the slugs; sometimes it is almost aborted, as in the 
oysters ; but more or less it is always present, and it is the 
characteristic organ of the mollusca. 

Attached to the foot in the gastropods is the operculum, the 
plate with which when the animal withdraws into his shell he closes 
the mouth. It is not always present and not always solitary ; some- 
times in specimens of Buccinum undatum there are two or three 
opercula. It is absent in all the British land shells, except 
Cyclostoma and Acicula. It used to be considered as representing 
the second valve in the bivalves, but it is not produced by the 
mantle ; by others it was regarded as corresponding to the byssus, 
that bunch of horny threads used as a means of attachment by the 
mussels, etc., but it differs from it in not being due to a special 
gland. It varies in composition, being of almost every intermediate 
grade between horn and shell, and it is of all degrees of thickness 
and of many shapes, ranging from a mere thin flake to what looks 
like a well-formed discoidal shell. In the land shells it is repre- 
sented by the epiphragm, which is a stopper of hardened mucus 
secreted by the liver cells, and formed only during periods of 
inactivity as a protection from the weather or the enterprising 
enemy. 

The shell is secreted by the mantle, which is an expansion of the 
integument on the upper side. Each layer of the shell was once a 



UNIVALVES. 49 

portion of this covering, either in the form of a membrane or a 
cellular layer. Every part of the mantle can secrete shelly matter, 
but the work is mostly done by the margin, where the colour cells 
also lie. Occasionally the mantle edges turn up over the shell 
sufficiently far as to meet, and then the shell becomes internal. In 
the slugs this is shown in an advanced stage ; in Avion the shell has 
disappeared all but a few granules; in some families it has 
disappeared altogether. 

Nearly every form of spiral is represented in the class, from the 
flat disc to the narrow tube with almost parallel sides, and from whorls 
as close as those of a paper spill to whorls that nowhere tench each 
other ; the majority right-handed, but many left-handed, and some 
with every intermediate stage between right and left, showing how 
the reversal has come about. The shell grows with the animal, 
who sometimes moves downwards from the upper whorls and leaves 
them decollate, as it is called, that is to decay and drop off. As it 
grows the periods of rest are marked by the lines of growth, and in 
some cases by either the thickening of the lip, which afterwards 
varies the surface with what is known as a varix, or by the row of 
spines which once fringed the mouth. 

When young the lip is thin, but with age it usually thickens into 
a rib or is toothed or curved. The mouth is of every intermediate 
shape between a parallel gash and a circle, and is either with or 
without a notch or canal. When there are two of these notches or 
canals, that on the anterior side generally takes the siphon, while 
that on the posterior side carries the vent. When the mouth is not 
notched it is said to be entire, and this in most cases shows the 
animal to be a plant-eater, the notches or canals being generally 
distinctive of the carnivorous forms. 

The mouth of the animal affords a similar guide to habits, 
although not so frequently, the vegetarians having the mouth on the 
surface of the head, while the flesh-eaters carry it on a proboscis ; but 
there are many exceptions to this. This mouth not the mouth of 
the shell is furnished with lips which in many cases are extensile. 
In the bivalves it opens at once into the gullet, but in the rest of the 
class it leads into a pharynx, which is fitted with jaws for biting the 
food, and with a lingual ribbon, otherwise known as a radula or 
odontophore, with which the food is scraped into a triturated mass 
before it passes down the gullet into the stomach. The jaws are 
distinctive, not only of the genus but of the species ; those of the 
freshwater pulmonates are recognisable at once by their pair of 
accessory side plates. 

The radula consists of a series of hook-like teeth, made of chitin, 
the same substance as that of which the ligament of the bivalves is 
composed, and it is generally silvery-white, tipped occasionally with 
red or yellow. As it wears away in front it is pushed up by the new 
rows of teeth forming behind. Sometimes the worn-out teeth in 
front do not drop off, but are preserved in a special sac, the askos, 
from which the sub-order to which their species are assigned derives 
its name of Ascoglossa. In Eulima, Stilifer, and Odostomia, among 
others, the lingual ribbon is missing, and hence their genera are 
grouped as Gymnoglossa. The radula is also missing in the sea- 
hares and other nudibranchs, and a few more. 



50 UNIVALVES. 

In the ordinary radula the ribbon consists of five rows of teeth, 
the central or rachidian, the laterals on either side, and the marginals 
at each edge. The rachidian is generally present ; some genera 
have lost both it and the laterals ; some have lost both laterals and 
marginals. One genus has but one tooth ; in others the number 
runs into thousands. Buccinum undatum, for instance, has about 
250, Limncea stagnalis has over 8,000, Helix aspersa has about 15,000 ; 
in some of the Mediterranean species there are nearly three-quarters 
of a million. The radula is now used largely as a basis of classifi- 
cation. The Toxoglossa, represented in the British list by Mangilia 
and Pleurotoma, the ribbon is made up entirely of the marginals, 
which are largely developed. The Rachiglossa, represented in our 
list by Trophon, Murex, Purpura, Lachesis, Columbella, Nassa, 
Buccinum, Buccinopsis, Fusus, and Marginella, there is a central tooth 
with a single lateral. The Taenioglossa, comprising the species we 
have numbered from 370 to 460, that is, from Natica to Triton, have 
a rachidian, a lateral, and two marginals. In the Ptenoglossa, 
represented in our list by lanthina, Scalaria, and Aclis, the radula 
consists of an indefinite number of hooked teeth with the largest on 
the margin. In the Rhipidoglossa, of which the British genera are 
Fissurella, Puncturella, Emarginula, Hahotis, Scissurella, Cyclostrema, 
Trochus, Phasianella, and Neritina, the laterals vary in number from 
nine to three, and the marginals are many and large. In the 
Docoglossa, represented with us by Tectura, Lepeta, Propilidium, 
Patella, and Helcion, the laterals and marginals are occasionally 
wanting, and the teeth are thick and beam-like. In Lepeta and 
Propilidium there is the usual central tooth, but in Patella this is 
replaced by four teeth, and in other genera by two. The ribbon in 
this group is lengthy ; that of the common limpet is made up of 
180 rows. This, however, is not the extreme length known; the 
periwinkle, for example, belonging to the Tsenioglossa, has a radula 
2^ inches long, containing 600 rows. For the purpose of describing 
these molluscan teeth concisely, a dental formula has been adopted 
on the ordinary lines ; Lepeta, for instance, is given as 2, o, i, o, 2, 
meaning 2 marginals on each side, no laterals, and i central tooth. 
In the other orders the teeth also differ in number and character, 
but this rapid glance at the seven sub-orders of the Prosobranchiates 
must suffice us. 

The Prosobranchiates derive their name from the veins con- 
nected with the branchiae being situated in front of the ventricle of 
the heart, those of the Opisthobranchiates being placed behind the 
ventricle. All the mollusca have a heart ; sometimes it consists of 
a single auricle and ventricle, as in the Monotocardia ; sometimes 
there are two auricles, as in the Chitons and the Diotocardia; some- 
times there are four, as in the Nautilus ; in all cases the number of 
auricles being the same as that of the branchiae, by which the blood 
is aerated as it passes on its way. 

The land mollusca breathe air, the water mollusca breathe 
water ; but the freshwater mollusca that are without an operculum 
breathe air, though they live in the water, and take it down with 
them in bubbles on their visits to the surface, while the water 
mollusca that live within the tide range retain enough water for 
them to breathe until the return of the tide. Thus the mollusca 



UNIVALVES. 51 

may be said as a whole to breathe by gills, by lungs, and by the 
outer skin. 

The Pulmonates, those that breathe by lungs, are divided into 
two sub-orders the Basommatophora, in which the eyes are 
generally at the base of the tentacles, and the Stylommatophora, in 
which the eyes are at the tip of the tentacles. We have already 
mentioned the Prosobranchiates, with their two sub-orders of 
Diotocardia and Monotocardia, the first divided into Docoglossa 
and Rhipidoglossa, the second into Pteno , Taenio , Gymno , 
Rachi , and Toxoglossa ; and the only gastropodous order left is 
the Opisthobranchiates, one sub-order of which, Ascoglossa, has 
also been mentioned, the others being the Tectibranchs, the 
Nudibranchs, and the Pteropods. 

The Pteropods used to have an order all to themselves, but are 
now claimed to be gastropods adapted to a pelagic life by the 
modification of their foot into fins. Only three of their species are 
recognised as British. The Nudibranchs are the sea-slugs, gorgeous 
in protective colouring, that have no shell in the adult state and 
breathe either by the skin or by the organs developed on the back, 
which give them their characteristic appearance. The Tectibranchs 
have a shell more or less rudimentary and more or less enveloped in 
the foot or mantle, and their breathing is done by a single gill, also 
more or less covered by the mantle. 

Between the Pelecypods and the Gastropods there are now 
placed the Scaphopods, which, unlike them, are not divided into 
orders, and consist of but one family, the Dentaliidae. In our seas 
but three genera are represented, two of which are very rare. 
Dentalium, the common one, has a shell like a model elephant's 
tusk, some ten times as long as its diameter. The shell of Siphono- 
dentalium is also tusk-like, but not more than five diameters in 
length, and further distinguishable by the four notches at its base. 
Cadulus is of a different shape, as can be seen by the drawing, and 
neither of them is likely to be mistaken for Dentalium. 

In the Scaphopods the mantle has two folds to begin with, and 
these become united so as to deposit the cylindrical shell, which is 
open at both ends, the larger being the anterior, from which the 
long foot with its three terminal lobes is protruded, on which the 
animal creeps and by which it burrows in the sand. The head is 
small and cylindrical, the mouth surrounded by tentacles and in it 
a simple radula. The ventral side is the convex side. There is a 
blood circulation, but no heart ; there are plenty of nerves, and, at 
least, an organ of hearing ; and the sexes are separate. Simple as 
the elephant's tooth may look, it is highly organised enough to 
be placed by some near the Cephalopods, with the Gastropods 
below it. 

The shell of a gastropod may be divided into body-whorl and 
spire, as in the annexed diagram. The spire may consist of any 
number of whorls, increasing in size from the apex downwards. At 
the apex the shell began, and each whorl in turn was the body-whorl. 
The suture is the line of junction between the whorls, and it descends 
all the way from the apex to the mouth. As the shell grew the inner 
side of its whorls formed the columella or central pillar, around 
which they are arranged like steps in a spiral staircase. The mouth 



52 UNIVALVES. 

has its two lips, inner and outer ; the outer one being often toothed, 
the inner being occasionally so. At the base is the canal, which in 
our example is very short and abrupt, but which in some genera is 
of considerable length, in others represented by a mere notch, and 
in many absent altogether. This is the anterior canal; in a few- 
cases there is another canal, the posterior one, which is at the 
opposite side of the mouth. 

The mouth has many varieties a few of them are shown in our 
illustration and we will use it as our chief aid in identification, 
beginning with those shells in which it has neither notch nor canal. 
There are a few forms it will simplify matters to get out of the way 
at the outset. For instance, there are two tubular shells, Dentalium 
and Cczcum. Dentalium and its allies we have already dealt with. 
Ccecum, which is a very small affair, is like a section of Dentalium 



Suture .'"- 



Body whorl 




"*" Outer lip 



Canal 



PARTS OF A UNIVALVE SHELL. (Nassa reticulata.) 



when fully grown, for it loses its spire very early in life, and thus 
reduces itself to a straight or slightly curved cylinder. 

One genus, Natica, has a shell that is so markedly globular as to 
be at once distinguishable from the others. Four genera have shells 
that are ear-shaped. Of these, Haliotis can be sorted out at once 
from its large size and from its perforated lip. Through these per- 
forations pass the tentacular appendages of the mantle, and as the 
animal grows the early holes are successively obliterated. Haliotis 
is represented in the British list by the one species tuberculata, which 
is frequently described as purely a Channel Islands native, but the 
specimen figured in our coloured plate came from South Devon. 



UNIVALVES, 



53 







Nahcasordula Trochu^aqu, 

VARIETIES OF THE MOUTH. 



54 UNIVALVES. 

The ear-shaped shells with an unperforated lip may be divided into 
Whorls twoOtina. 

Whorls more than two 

Very thin and transparent 

First whorl twisted Lamellaria. 

Rather thin and opaque 

First whorl not twisted Velutina. 

Otina is very frail, and about a tenth of an inch in height and 
diameter, being in shape not unlike a cap of liberty. The others 
are much longer, Lamellaria measuring almost three-quarters of an 
inch, and Velutina, of which there are two species, averaging half 
an inch or more. 

There are thirteen genera whose shells can fairly be classed as 
cap-shaped, like that of the limpet. Two of these are oblong in 
shape, Ancylus and Testdcella, the first being the fresh-water limpet, 
the other the carnivorous slug which carries the shell jauntily on 
the back of his tail. This shell is ridiculously small for the size of 
the animal, and, like those of all the ^slugs, is the representative of 
something much larger in the past. In Ancylus the crown is in the 
middle, in Testacella it is on the right-hand side, and the mouth of 
Ancylus is quite open, while that of the other is folded under along 
the side beneath the crown ; in fact, the differences are strongly 
marked, though our sorting has brought the two genera together. 

Two of the group have a curled and twisted beak. These are 
Crepidula and Capulus, the first of which has a septum across the 
mouth, the other having the mouth free. Both shells are somewhat 
oblong, but Crepidula is longer in the line of the beak, while Capulus 
is longer across that line. Capulus is a stout, sturdy, independent 
sort of a shell ; Crepidula, the slipper limpet, is a parasite, and found 
its way into the British list from having been found on the American 
oysters transplanted to this country, and a specimen on the oyster 
is in the London Natural History Museum. 

Another group of three genera can be recognised as being slit. 
Fissurella has the slit at the crown, Emarginula has the slit on the 
margin, and Puncturella has the slit between margin and crown. In 
Puncturella the beak is twisted to the left, and the slit so covered by 
an internal sheath that it is not at first very clear ; in Emarginula 
the slit is apparent at once, as it makes a. clear cut in the edge of the 
shell, and extends inwards for an appreciable distance. 

Two genera have the crown near the front margin. Of these, 
Tectura is much depressed, while Helcion is almost as high as it is 
long. Tectura is like the roof of a house, Helcion like a lady's 
bonnet ; one coarse and weather-beaten, the other bright and glossy, 
and beautifully streaked with narrow radiations of blue. In a group 
by itself, with the crown almost central, but not quite, we can put 
Patella, the common limpet, which is unmistakable in its many 
varieties. Looking at the margin of Patella you can tell whether his 
home is hard or soft. If the rock be hard, he modifies his margin to 
suit it ; if it be soft, he scoops it out into a pit so deep that little 
more than the crown appears above it, and the crown this is the 
important point is never quite in the centre. 



UNIVALVES. 55 

With another group of three, in which the crown is exactly 
central, we can end the cap-shaped genera, so far as Britain is 
concerned. The three are Lepeta, which is white inside and out, 
and has no shelf in its mouth ; Propilidium, which has a shelf and is 
oval ; and Calyptrcea, which has a spiral diaphragm within it, and is 
round and low-crowned, like a Chinaman's hat. 

We may as well tabulate this cap-shaped thirteen : 

Oblong 

Pillar fold broad Testacella. 
Pillar fold indistinct Ancylus. 

Beak twisted 

Mouth with septum Crepidula. 
Mouth without septum Capulus. 

Shell slit- 
Slit at crown Fissurella. 
Slit on margin Emarginula. 
Slit between crown and margin Puncturella. 

Crown central 

With spiral diaphragm Calyptrcea. 

With shelf Propilidium. , 

Without shelf or diaphragm Lepeta. 

Crown nearly central Patella. 

Crown near anterior margin 

High and streaked with blue Helcion. 
Low and not streaked Tectura. 

Next we will take the shells that have a toothed margin ; two of 
these are sinistral, that is, have left-handed spirals, and one of them 
has a clausilium, whence its name Clausilia, while the other, Balea, 
has not the clausilium being an internal plate attached to the pillar 
of the shell, which can be used to close the entrance, and which 
differs from the operculum in not being attached to the animal's 
foot and thus protruded beyond the shell. Two others are almost 
cylindrical in shape, and look like little beads, these being Vertigo, 
with an angulated mouth, and Pupa, wrth a mouth that may be ovate 
or lunate, but is never angulated. One of the Helices, Helix obvoluta, 
may be mentioned next, the only Helix that has a tooth. Then we 
have three oval shells Cochlicopa, in which the mouth is pear- 
shaped ; Carychium, in which it is obliquely oval ; and Melampus, in 
which it is narrow and the pillar has folds. Of these, Carychium is 
transparent and the others are not, except one greenish variety of 
Cochlicopa, and Cochlicopa can at once be distinguished from 
Melampus by the absence of folds on the pillar. 

We will now take the flat shells that are coiled like a rope on a 
ship's deck. Three of these have a circular mouth. In one, Homa- 
logvra, the mouth clasps the periphery ; in another, Planorbis, the 
mouth is thickened with a rib ; and the other, Valvata, has no rib. 
The rest of the flat shells belong either to Helix or Planorbis ; those 
with a mouth of four-fifths of a circle without a rib, or quadrangular 



56 



UNIVALVES. 




Aporrhais 

per-pelecan; 



Fusus isUndica 



LIVING SHELLS. 



UNIVALVES. 57 

or horseshoe-shaped, belong to Helix; the others with the mouth 
oval and oblique, or oval and angulated, or half-moon shaped with 
a rib, or two -thirds of a circle with rib, belong to Planorbis. 

We can now attack the main body of the Gastropods those 
whose shells are a raised spiral. From these we can at once pick 
out Aporrhais, which has the pillar projecting beyond the mouth, 
and the outer lip expanded into the winged or digitate process as 
broad as the diameter of the shell, so clearly shown in our illustra- 
tion of living shells. And with it we can put Cerithium and 
Cerithiopsis, in which the pillar slightly projects, but the lip is not 
digitate, and which can be distinguished from each other by the 
basal groove, the first having it curved and the second having it 
straight. This leaves us with the holostomatous shells, in which the 
pillar does not extend beyond the mouth. Clearing off Stilifer, in 
which the apex is divided into two, Truncatella, in which it is broken 
off short, and Scissurella, in which there is a slit in the outer lip, we 
can make three groups of the rest : 

Height less than breadth. 
Height equal to breadth. 
Height greater than breadth. 

And sub-divide the last into : 

More than double the breadth. 
Between double and treble. 
More than treble. 

Less than double the breadth. 

Those in which the height is less than the breadth comprise 
certain species of Helix, in which the mouth is semi-circular; 
Cyclostrema, in which it is nearly circular ; Vitrina, in which the 
shell is thin and green ; Skenea, in which it is thin and opaque, with 
a flexuous, projecting mouth ; and Zonites, which is thin, trans- 
parent, shining, with an oblique mouth of the shape of a crescent. 
Add to them the two flat-based genera, Adeorbis and Trochus, the 
first of which is minute, and is further distinguishable by its waved 
lip, and we have all this batch which are broader than they are 
high. Briefly, they can be put as follows : 

Base flat 

Outer lip plain Trochus. 
Outer lip waved Adeorbis. 

Base not flat- 
Thin and green Vitrina. 
Mouth flexuous and projecting Skenea. 
Mouth crescentic and oblique Zonites. 
Mouth semi-lunar Helix. 
Mouth almost circular Cyclostrema. 

In the next group, that which are as broad as they are long, if we 

E 



58 UNIVALVES. 

take away lanthina, unmistakable owing to its violet shell, we are 
left with six genera : 

Base flat Trochus. 
Mouth circular Valvata. 
Pillar folded Limnaa. 
Pillar grooved Lacuna. 
Thick and heavy Littorina. 
Thin and light Helix. 

Those in which the height is greater than the breadth are not so 
easily disposed of. Some are between double and treble as long as 
they are broad, some more than treble as long. The longest in our 
list are Odostomia, Eulima, Aclis, Turritella, and Scalaria. The left- 
handed upper whorls distinguish Odostomia; Eulima is narrow and 
pointed as an awl, and highly polished ; Aclis is smooth or faintly 
ridged and pyramidal in form ; Turritella has bold spiral ridges, and 
Scalaria prominent longitudinal ribs, added to which Turritella is the 
longest narrow shell we have. 

The next batch, those having the length between less than three 
times but more than twice the length*, comprises Odostomia, with its 
sinistral upper whorls ; Limncea, with its folded pillar ; Bulimus, with 
its reflected outer lip; and Acicula, with its reflected inner lip, 
A cicula, better known as A cme, being a land shell with an operculum. 
We can put the long eight under one heading to simplify matters : 

Upper whorls sinistral Odostomia. 
Pillar folded Limn&a. 
Outer lip reflected Bulimus. 
Inner lip reflected Acicula. 
Subulate and polished Eulima. 
Smooth or faintly ridged Aclis. 
Spirally ridged Turritella. 
Longitudinally ribbed Scalaria. 

We are left with those longer than they are broad, but not twice 
so long as they are broad. These we can divide into those having 
the curve of the mouth broken into by the body whorl, and those in 
which it is not interfered with ; in other words, those with an 
incomplete peristome and those with a complete peristome. The 
incomplete ones are Limncza, Bulimus (as regards obscurus), Neritina, 
and Jeffreysia, whose differences can be thus summarised : 

Pillar with fold Limnaa. 

Mouth like a horseshoe Bulimus. 

Shell thin, smooth and glossy Jeffreysia. 

Shell semi-globular, mouth semi-circular Neritina. 

Size alone will sort out Jeffreysia, as none of its three species are 
larger than the tenth of an inch, and the mouth of Neritina and the 
fold of Limncea leave Bulimus conspicuously alone. 

Those with peristome complete are more numerous. At the first 
glance we can pick out Lacuna, with its grooved pillar ; Physa, with 



UNIVALVES. 59 

its left-handed shell; the amber-coloured Succinea, in which the 
mouth is more than half the shell's height ; the richly variegated and 
polished Phasiandla ; and Assiminea, with its inner lip thick and 
outer lip thin. Seven genera are left. In two of these the shell is 
thin Bithynia, which has a thick outer lip, and Hydrubia, which has 
a thin outer lip. In three the shell is moderately thick ; one, 
Cyclostoma, having a nearly circular mouth, the other two being 
separable on size alone, Rissoa never exceeding half an inch, and 
Viviparus, otherwise Paludina, never measuring less than an inch. 
This reduces the seven to two in which the shell is particularly 
solid ; and it is smooth in Barlee'm and heavy and striated in 
Littorina, as everyone knows who has picked up a periwinkle. 

With that we end the British gastropods having entire mouths, 
among whom are included all our land and fresh-water shells but 
one. That one is Achatina acicula, which can be distinguished from 
the rest of the notched group by its transparency. It is a diminutive 
species, not much more than an eighth of an inch long, and seldom 
found alive owing to its living underground among the roots of the 
trees and plants. It has no eyes, and its lower tentacles are only 
discoverable with difficulty as a pair of almost invisible knobs, and, 
with its thin white shell, is altogether a most unexpected representa- 
tive of a genus which contains over 400 species, mostly African, 
including the largest of living land-snails, which is more than six 
inches in length. 

Leaving the land for the sea, we can divide the non-trausparent 
group into 

Shell convolute. 

Shell with a long narrow mouth. 
Shell with a curved canal. 
Shell with a straight canal. 

Those with a convolute shell are three in number, and in two of 
them the spire is hidden. These are Ovula and Cyprcea, the cowry. 
In the cowry the outer lip is ribbed, in Ovula it is plain. Although 
we have thus brought them together, owing to their being convolute 
and having hidden upper whorls, their shape is very different, as can 
be seen in the illustrations ; and the cowry is so well known that it 
would almost be sufficient to say that the pair consists of the cowry 
and another, for there is only one species of each. In one other 
convolute shell, Marginella, the spire is not turned in, but is very 
low. It looks like a cowry that had thought better of it, and is a 
singularly graceful little shell, bright and polished, and ribbed only 
on the outer lip, the rib being very faint. As with the other two, 
we have only one species of the genus, that being Icsvis. Briefly 
then we have : 

Shell convolute 

Spire not hidden Marginella. 
Spire hidden. 

Outer lip plain Ovula. 

Outer lip ribbed Cypraa. 



6O UNIVALVES. 

In the remainder of our shells the lip is not turned inwards. 
Three of the genera are spindle-shaped, and have a long, narrow 
mouth. In one the mouth is smooth, in another it is grooved, in 
the other it is ridged. In the first the outer lip is notched, in the 
last it is curved. This will serve to distinguish them, thus : 

Mouth smooth, outer lip notched in the middle Pleurotoma. 
Mouth grooved, outer lip notched at top Mangilia. 
Mouth ridged, outer lip curved Lachesis. 

In this triad, the slit in the mouth ought to mark off the two first at 
once, but the writer has not been fortunate enough to find it always 
in Mangilia, and only once or twice in Pleurotoma', doubtless it was 
there, but it was too faint to talk about, in some specimens at all 
events. In Mangilia it comes just where the lip joins the periphery. 
In both genera, as usually figured, it is unmistakable. Lachesis has 
a shorter mouth than the other two, and is a heavier, clumsier sort 
of shell about the same size, easily distinguished from the others by 
its thick mouth. Mangilia, it may be as well to say, is quite as well 
known as Defrancia, and is as often 'spelt Mangelia, a name which 
was at one time applied to Pleurotoma. 

In our next two groups the month is broken by a long notch, 
which may be called a canal. In some cases this canal is curved, 
in others it is straight. It is curved in four genera, Columbella, 
Nassa, Buccinum, and Buccinopsis. Of these the first can be 
recognised by the fold at the base of the pillar, and by the curious 
projection of the outer lip alongside the notch. Nassa has the 
curvature of the canal distinctly shown, and has a characteristic 
tooth or teeth at the base of the pillar. In the other two genera the 
pillar is smooth, the difference being that in one, Buccinum, the 
whelk, the shell is coarsely ribbed ; in the other, Buccinopsis, very 
like a whelk, the shell is finely striated. Putting them into form, 
we have: 

Shell with curved canal 

Pillar folded at base Columbella. 
Pillar toothed at base Nassa. 

Pillar smooth 

Coarsely ribbed Buccinum. 
Finely striated Buccinopsis. 

There are five genera in which the canal is straight, and in one 
of these, Murex, it is covered in so as to form a tube. Murex can 
be identified at a glance by this tubular canal. Of the four with the 
canal open, one, Triton, has the pillar with folds or tubercles, and 
the shell is coarsely ribbed with very prominent varices. Both 
species are large, being two or three inches long, and both are rare 
as British specimens, and appear in our list as being found in the 
Channel Islands. Among shells in general they are as well known 
as any, being as old as Neptune, however old that may be, that sea- 
god having used them before his trumpeter died. 

The three in which the pillar is smooth can be sorted out as 
those in which the canal is long and those in which it is short. It 



UNIVALVES. 6l 

is long in Fusus, the large smooth whelk, and in Trophon, and it is 
short in Purpura. Purpura lapillus, the dog-whelk, is a massive 
little shell, not unlike a periwinkle in its typical form, with an oval 
mouth and thin, deeply-cut, short canal. Periwinkles vary, and so 
do dog-whelks ; in fact, the variations of the latter are so numerous 
as to be nameless, and, in some cases, unrecognisable as belonging 
to the species in the absence of the intermediate forms. The other 
Purpura is a much more gentlemanly shell, and is of graceful build, 
with a rich orange mouth ending in a shorter canal than lapillus. 

Though Trophon has prominent ribs, and Fusus has not, the 
readiest means of distinguishing between them is by their size. 
Trophon is never over an inch in length, Fusus is never under an 
inch, and in some species runs up to five inches. The specimen of 
Fusus antiquus figured in the coloured plate, which is of the variety 
alba, is just five inches long, and the smallest species, propinquus, 
with the turreted spire, is well over an inch and a half. Let us note 
this further step in the usual form : 

Canal straight and open 

Pillar folded or tuberculated Triton. 
Pillar smooth. 

Canal short Purpura. 

Canal long. 

Shell under an inch Trophon. 
Shell over an inch Fusus. 

We have only two genera left, both represented by only one 
species, and both belonging to the same family, though very unlike in 
appearance, and being the only British representatives of that 
family. They are brought together here simply because in each 
case the shell has an indistinct notch, which prevented them being 
dealt with in our first series. The first, Trickotropis, is pointed at 
both ends, with a mouth expanding upwards, and has prominent 
spiral ribs that are cut across by thread-like striations ; the other, 
Torellia, is not unlike a rounded periwinkle in shape, with a mouth 
expanding downwards, and having no ribs, but being finely striated 
in both directions. With Torellia we have the last of the eighteen 
British genera that have the mouth interrupted by a notch or canal. 

This is not all the British shells. There is another series among 
the opisthobranchs, some of which have shells, while others have 
not. In three genera, Philine, Aplysia, and Pleurobranchus, the 
shells are ear-shaped and very thin ; in Philine the shell is white, in 
Aplysia it is broad, horny, and glossy, in Pleurobranchus it is broad 
and iridescent. In two genera it is convolute, Cylichna having the 
spire hidden, and Tornatinus, otherwise Utriculus, having the spire 
exposed. In two species the shell is almost convolute, these being 
Scaphander, with it spirally striated, and Acera, with it swollen and 
thin. In two cases the shell is oval in general outline, these being 
Actceon, in which it is spirally striated, and Bulla, in which the spire 
is involute. Both Action and Scaphander have substantial shells of 
ordinary appearance, though, in the case of Scaphander, of peculiar 



62 UNIVALVES. 

shape; those of Accra and Bulla are not unlike that of Limncza in 
colour and material ; those of Cylichna and Tornatinus are small and 
distinctive ; those of Philine, Aplysia, and Pleurobranchus are mere 
membranes. The sea- slugs have no shells, and, as in their case it is 
not worth going over the same ground twice, we will leave their 
points of identification to be dealt with under their families and 
genera further on. 

The land-slugs have shells, but they are internal and rudimentary, 
and dwindle down to a few granules, to show that a shell was 
possessed by distant ancestors. The easiest way to identify the 
slugs is by their breathing aperture. In Geomalacus, the spotted 
slug hailing from the south-west of Ireland, which is the connecting 
link between Limax and Arion, the aperture is near the front of the 
shield. In Arion it is in the middle of the shield. In Limax and 
Amalia, a genus formerly included with Limax, it is near the back of 
the shield, Amalia having the mantle granulated, Limax having it 
striated. If you are in doubt as to which is the mantle, you have 
only to irritate a Limax to see him duck his head under his mantle, 
or catch him asleep, when you will find he has put his mantle over 
his head to make himself comfortable. 

It will be noticed that we have grcTuped our land slugs under five 
genera Testacella, Amalia, Limax, Arion, and Geomalacus ; and of 
these genera recorded seventeen species. Had we included varieties 
we should have had fifty more figures, and even then we should not 
have illustrated them all or made clear the difference between them. 
Had we given the varieties of all the species, marine and non- 
marine, we should have required two thousand illustrations, to 
include only those distinctive enough to be worth regarding. 

Among the molluscs it is more difficult than usual to draw the 
line between a variety and a species, or even between one variety 
and another. Several of the species are old varieties promoted to 
the higher rank, and, as a rule, it is desirable to keep new forms 
among the rank and file until the reasons for their promotion are 
strong enough to satisfy the reasonable. As instances of promotion, 
we have Helix hortensis, looked upon for years as a variety of Helix 
nemoralis, and as an example of the intermediate stage, we have 
Testacella scutuhtm, accepted as a species by some, and retained by 
others in its old place as a variety of Testacella haliotidea. 

Varieties are the general collector's horror and the specialist's 
delight. To have dealt with them in this book would have made it 
too heavy in two senses, and so we restricted it to the species only, 
and we have also simplified the path of identification by keeping 
clear of sub-genera, which are rather as luxuries than necessities. 
Dealing with one country's fauna, as we do, the old genera are not 
too large for our purpose ; but dealing with the world's fauna, such 
a genus as Helix, for instance, becomes too crowded with species to 
be wieldy, and the species sort themselves into unmistakable groups 
for which a collective name is manifestly a convenience. Such 
names have, consequently, been adopted, and, in due course, have 
found their way into our local lists. They would be used in all 
cases if there were any indications of permanence amongst them, but 
of the making of sub-genera, as of the making of species, there seems 
to be no end. Hence the generic name is usually retained, and the 



UNIVALVES. 63 

species arranged in groups under the sub-generics. Occasionally 
the generics are dropped, and the collector finds himself confronted 
with names unknown to him that he can find no mention of in his 
books, and which in some cases appear to have been suggested 
mainly for the sake of the little advertisement in brackets that it is 
hoped they will always carry with them. 

But synonymy is inevitable, and there is no good in girding at it. 
It is a large matter, and, as a complete synonymy of our mollusca 
would probably have filled all our pages, it is here impossible ; but 
as a help in times of trouble we may find space for the following 
short working list of some of the more recent synonyms of the 
British pulmonates : 

Acanthinnla aculeata Helix aculeata, 263. 
Acanthinula lamellata Helix lamellata, 274. 
Agriolimax agrestis Limax agrestis, 235. 
Agriolimax Isevis Limax laevis, 236. 
Alinda biplicata Clausilia biplicata, 504. 
Alcea alpestris Vertigo alpestris, 292. 
Alcea antivertigo Vertigo ajitivertigo, 294. 
Alosa moulinsiana Vertigo moulinsiana, 298. 
Alcea pygmaea Vertigo pygmaea, 500. 
Alcea substriata Vertigo substriata, 501. 
Amalia sowerbyi Amalia marginata, 233. 
Amphipeplea glutinosa Limnaea glutinosa, 209. 
Aplexa hypnorum Physa hypnorum, 229. 
Arianta arbustorum Helix arbustorum, 264. 
Arion circumscriptus Arion bourguignati, 242. 
Azeca tridens Cochlicopa tridens, 311. 
Bathyomphalus contortus Planorbis contortus, 218. 
Buliminus montanus Bulimus montanus, 261. 
Buliminus obscurus Bulimus obscurus, 262. 
Chilotrema lapicida Helix lapicida, 275. 
Clausilia bidentata Clausilia rugosa, 307. 
Cochlicella acuta Bulimus acutus, 259. 
Ccecilioides acicula Achatina acicula, 312. 
Conulus fulva Zonites fulvus, 253. 
Coretus corneus Planorbis corneus, 219. 
Fruticola cantiana Helix cantiana, 266. 
Fruticola cartusiana Helix cartusiana, 268. 
Fruticola fusca Helix fusca, 271. 
Fruticola granulata Helix sericea, 286. 
Fruticola hispida Helix hispida, 272. 
Fruticola revelata Helix revelata, 282. 
Fruticola rufescens Helix rufescens, 284. 
Gonostoma obvoluta Helix obvoluta, 277. 
Gyraulus albus Planorbis albus, 215. 
Gyraulus dilatatus Planorbis dilatatus, 220. 
Gyraulus nautileus Planorbis nautileus, 223. 
Gyraulus parvus Planorbis glaber, 221. 
Gyrorbis carinatus Planorbis carinatus, 216. 
Gyrorbis complanatus Planorbis complanatus. 217, 
Gyrorbis spirorbis Planorbis spirorbis, 225. 



64 UNIVALVES. 

Gyrorbis vortex Planorbis vortex, 226. 
Helix granulata Helix sericea, 286. 
Helix itala Helix ericetorum, 270. 
Hippeutis nitidus Planorbis nitidus, 224. 
Hyalinia alliaria Zonites alliarius, 249. 
Hyalinia cellaria Zonites cellarius, 250. 
Hyalinia crystallina Zonites crystallinus, 251. 
Hyalinia draparnaldi Zonites draparnaldi, 248. 
Hyalinia excavata Zonites excavatus, 252. 
Hyalinia fulva Zonites fulvus, 253. 
Hyalinia glabra Zonites glaber, 254. 
Hyalinia nitidula Zonites nitidulus, 256. 
Hyalinia nitida Zonites nitidus, 255. 
Hyalinia pura Zonites purus, 257. 
Hyalinia radiatula Zonites radiatulus, 258. 
Isthmia minutissima Vertigo minutissima, 297. 
Lauria anglica Pupa ringens, 289. 
Lauria cylindracea Pupa umbilicata, 291. 
Limax marginatus Limax arborum, 238. 
Lymnophysa palustris Limnaea palustris, 211. 
Lymnophysa stagnalis Limnaea stagnalis, 213. 
Lymnophysa truncatula Limnasa truncatula, 214. 
Marpessa laminata Clausilia laminata, 505. 
Patula rotundata Helix rotundata, 283. 
Patula rupestris Helix rupestris, 285. 
Pirostoma bidentata Clausilia rugosa, 307. 
Pirostoma rolphii Clausilia rolphii, 306. 
Polita draparnaldi Zonites draparnaldi, 248. 
Polita glabra Zonites glaber, 254. 
Polita nitidula Zonites nitidulus, 256. 
Polita pura Zonites purus, 257. 
Polita radiatula Zonites radiatulus, 258. 
Pomatia aspersa Helix aspersa, 265. 
Pomatia pomatia Helix pomatia, 279. 
Punctum pygmaea Helix pygmasa, 281. 
Pupa anglica Pupa ringens, 289. 
Pupa cylindracea Pupa umbilicata, 291. 
Pupa muscorum Pupa marginata, 288. 
Pupilla muscorum Pupa marginata, 288. 
Radix auricularia Limnaea auricularia, 207. 
Radix involuta Limnaea involuta, 210. 
Radix peregra Limnaea peregra, 212. 
Segmentina nitida Planorbis lineatus, 222. 
Sphceradium edentula Vertigo edentula, 295. 
Tachea hortensis Helix hortensis, 273. 
Tachea nemoralis Helix nemoralis, 276. 
Torquilla secale Pupa secale, 290. 
Vallonia pulchella Helix pulchella, 280. 
Velletia lacustris Ancylus lacustris, 205. 
Vertilla angustior Vertigo angustior, 293. 
Vertilla pusilla Vertigo pusilla, 299. 
Vitrea crystallina Zonites crystallinus, 251. 
Xerophila caperata Helix caperata, 267. 



UNIVALVES. 65 

Xerophila itala Helix ericetorum, 270. 
Xerophila pisana Helix pisana, 278. 
Xerophila virgata Helix virgata, 287. 

One more list, in conclusion. The following genera are non- 
marine that is, are either land or fresh-water. In our list of 
illustrations their names are set a quarter of an inch in, so as to 
distinguish them at a glance from the sea-shells : 



Pelecypoda 

Anodonta, 58, 59. 
Dreissensia, 60. 
Pisidium, 85 to 89. 
Sphaerium, 81 to 84. 
Unio, 55 to 57. 



Gastropoda. 

Achatina, 312. 
Acicula, 398. 
Amalia, 232, 233. 
Ancylus, 205, 206. 
Arion, 241 to 245. 
Balea, 303. 
Bithynia, 430, 431. 
Bulimus, 259 to 262. 
Carychium, 201. 
Clausilia, 304 to 309. 
Cochlicopa, 310, 311. 
Cyclostoma, 397. 
Geomalacus, 246. 
Helix, 263 to 287. 
Hydrobia 

as regards Hydrobia similis, 427, 

and Hydrobia ventrosa, 428. 
Limax, 234 to 240. 
Limnaea, 207 to 214. 
Neritina, 356. 
Physa, 227 to 229. 
Planorbis, 215 to 226. 
Pupa, 288 to 291. 
Succinea, 313 to 317. 
Testacella, 230, 231. 
Valvata, 441, 442. 
Vertigo, 292 to 302. 
Vitrina, 247. 
Viviparus, 439, 440. 
Zonites, 248 to 258. 



CHAPTER VI. 

TABULAR SCHEME, 



3 ETAINING the arrangement with which we began, we will put 
v the bivalves first, and begin with the Pholadacea : 

Shell with dorsnl pieces and apophyses 
Apophyses long 

Shell prickly all over Pholas, 160-163. 
Shell prickly only at fore end and with cup at posterior 
end Pholadidea, 164. 

Apophyses short Xylophaga? .165. 

Shell continued into a calcareous tube with long siphons, having 
a pair of calcareous pallets near the end Teredo, 166-171. 

We can then tabulate the group as follows : 
A. Pallial line not indented ; no siphons 

Shell inequivalve 

Equilateral or nearly so 
With ears Pecten, 33-43. 

Without ears 

With orifice in lower valve Anomia, 9, 10. 
Without orifice Ostrea, 32. 

Very oblique 

With teeth Avicula, 30. 
Without teeth Pinna, 31. 

Shell equivalve 
With ears- 
Hinge toothless ; one muscular scar Lima, 44-48. 
Hinge with teeth ; two muscular scars Limopsis, 
17, 18. 

Without ears 

Hinge with many teeth 
Hinge straight Area, 11-15. 

Hinge curved 

Shell round, teeth in two groups Pedunculns, 16. 
Shell elongated at posterior end, teeth on each 

side nearly equal Leda, 5-8. 
Shell trigonal, teeth much more numerous on 
posterior side Nncula, 1-4. 
66 



TABULAR SCHEME. 67 

Hinge with few or no teeth 

Shell almost circular Axinus, 66-68. 

Shell inequilateral 

Ligament external and large 
Teeth conspicuous Unto, 55-57. 
Teeth inconspicuous Anodonta, 58, 59. 

Ligament internal 

With radial ribs, transverse plates, and one 
upright tooth ; hinge margin crenulated 
behind the ligament Crenella, 24, 25. 
With two groups of strias from beaks 
Modiolaria, 26-29. 

Beaks terminal and pointed 

With shelf within the beak Dreissensia, 60. 
Without shelf Mytilus, 19-23. 



B. Pallial line not indented ; siphons short 

Grooves radial Cardium, 129-138. 

Grooves concentric 

Beaks twisted Isocardia, 54. 

Beaks not twisted 

Hinge without teeth Galeomma, So. 

Hinge with teeth 

Shell oblong Lcpton, 76-79. 

Shell triangular 

Two teeth in each valve Astarte, 50-52. 
Three teeth in each valve, one cloven so as to make 
the three look like four Circe, 113. 

Shell circular or sub-orbicular 

Ligament or cartilage internal 
Anterior scar long and extending within pallial 

line Loripes, 63, 64. 
Anterior scar orbicular Montacuta, 69-72. 

Anterior scar oval 

Left cardinal small Las&a, 75. 

Left cardinal thick and erect Kellia, 73, 74. 

Ligament more or less external 

Shell circular ; two teeth in each valve, anterior 
in left and posterior in right, being bifid ; 
ligament double Diplodonta y 65. 



68 TABULAR SCHEME. 

Ligament conspicuous 

Rising above level of dorsal line -Cyamium, 49. 
Partially overlapped in a groove 

Anterior scar narrow and projecting far within 

pallial line Lucina, 61, 62. 
Shell thick, large and heavy, scars oval and 
shiny Cyprina, 53. 

Ligament inconspicuous, shell horny and trans- 
lucent 

Beak at fore end Pisidium, 85-89. 
Beak midway Sphcerium, 81-84. 

C. Pallial line indented, siphons long 

Shell inequivalve 

Nearly equilateral, ligament in internal groove Lyonsia, 

I 73- 

Elongated at hinder end Pandora, 172. 

Truncated at hinder end 

Hinge with ossicle Thracia, 174-178. 
Hinge without ossicle, cartilage in cavity of cardinal 
C orb i' la, 146. 

Shell equivalve 

Gaping at both ends 

Shell long and narrow 

Hinge nearly midway, with radiating ribs Cerati- 

solen, 151. 
Hinge terminal, one cardinal in right valve Solcn , 

I52-I55- 

Hinge sub-terminal, two cardinals in right valve 

Solecurtus, 149, 150. 

Shell oblong and very oblique Lutraria, 147, 148. 
Shell broad with a broad, short shelf Mya, 7. 
Gaping posteriorly 

Beaks turned towards hinder end Scrobicttlaria, 

99-103. 
Shell striated radially and concentrically Psammobia, 

139-142. 

Shell with long, calcareous sheath Gasti'ochcena, 159. 
Shell with wrinkled periostracum extending over 

siphons Mya (as regards binghami, 145). 
Shell elongated, thin and prickly Petricola, 128. 
Shell with thin, concentric plates Venerupis, 127. 

Shell obliquely truncated at hinder end 
Pallial line continuous Panopcea, 158. 
Pallial line broken up-*-Saxicava, 156, 157. 



TABULAR SCHEME. . 69 

Cartilage in triangular cavity under each beak 
Shell with hinder end elongated Neczra, 180-183. 
Shell oval Poromya, 179. 

Not gaping at either end 

Ligament partly external, partly internal 
Teeth unequal in both valves Mactra, 108-112. 
Teeth unequal in right valve only Amphidesma, 107. 

Ligament wholly external 

Teeth two in right valve 

Inside margins notched Donax, 104-106. 

Inside margins not notched 

Teeth in left valve equal 

Shell as broad as long Lucinobsis. 122. 
Shell not so broad as long Talina, 90-97. 

Teeth in left valve unequal Gastrana, 98. 

Teeth three in both valves 

Sinus rounded Tapes, 123-126. 
Sinus angular Venus, 114-121. 

The bivalves being thus cleared from the path, we can take the 
other molluscs together 

Mouth of shell without groove or canal 
Shell multivalve Chiton, 190-200. 

Shell tubular- 
Pointed Dentalium, 187-189. 
Not pointed Ccecum, 453, 454. 

Shell globular Natica, 370-376. 

Shell ear-shaped 

Lip perforated Haliotis, 333. 

Lip not perforated 
Whorls two Otina, 204. 

Whorls more than two 

Very thin and transparent 

First whorl twisted Lamellaria, 377. 

Rather thin and opaque 
First whorl not twisted Velutina, 378, 379. 

Shell cap-shaped 

Oblong and solid, pillar fold broad Testacella, 230, 231. 
Oblong and thin Ancylus, 205, 206. 

Beak twisted and curled 

Mouth with septum Crepidula, 384. 
Mouth plain Capulus, 382. 



7O TABULAR SCHEME. 

Slit at crown Fissurella, 326, 327. 

Slit on anterior margin Emarginula, 329-332. 

Slit between crown and margin Puncturella, 328. 

Crown near front margin 

Streaked with blue Helcion, 325. 

Not streaked with blue Tectura, 319-321. 

Crown almost central Patella, 324. 

Crown quite central 

Without shelf Lepeta, 322. 

With triangular shelf Propilidium, 323. 

With spiral diaphragm Calyptrcca. 383. 

Shell toothed 

Sinistral 

'Mouth with clausilium Clausilia, 304-309. 
Mouth ovate Balea, 303. 

Cylindrical 

Mouth ovate or lunate Pupa, 288-291. 
Mouth angular Vertigo, 292-302. 

Depressed Helix (obvoliita), 277. 

Oval- 
Mouth pyriform Cochlicopa, 310, 311. 
M outh obliquely oval, shell transparent Carychium, 201, 
Mouth narrow, pillar with folds Melampus, 202, 203. 

Shell coiled flat- 
Mouth circular 
Without rib Valvata, 441, 442. 
Clasping periphery Homalogyra, 385, 386. 
Thickened with rib Planorbis, 216-218, 225, 226. 

Mouth oval and oblique, or 
Oval and angulated, or 
Semilunar with rib, or 
Two-thirds of a circle with rib Planorbis, 215-226. 

Mouth four-fifths of a circle, without rib, or 
Quadrangular, or 
Horseshoe-shaped Helix, 263-287. 

Shell a raised spiral 

Pillar projecting beyond mouth 
Outer lip digitate Aporrhais, 455, 456. 

Outer lip not digitate 

Basal groove curved Cerithium, 443-446. 
Basal groove straight Cerithiopsis, 447-45 1- 

Pillar not projecting 
Apex divided into two Stilifer, 467. 
Apex broken off short Truncatella, 399. 
Outer lip slit Scissurella, 334. 



TABULAR SCHEME. 71 

Height less than breadth 

Mouth almost circular Cyclostrem-a, 335-337. 

Thin and green Vitrina, 247. 

Thin and opaque, mouth flexuous and projecting 

Skenea, 434. 
Thin, transparent and shining, mouth obliquely cres- 

centic Zonites, 248-258. 
Mouth semilunar Helix, 263-287. 

Base flat 

Outer lip waved Adeorbis, 438. 
Outer lip plain Trochus, 338-354. 

Height equal to breadth 

Shell purple lanthina, 357-359. 

Shell conical with flat base Trochus, 338-354. 
Pillar folded Limncea, 207-214. 
Pillar grooved Lacuna, 392-396. 
Shell thick and heavy Littorina. 387-391. 
Shell thin and light Helix, 263-287. 
Mouth circular Valvata, 441, 442. 

Height more than double the breadth 

Between double and treble the breadth 
Pillar folded Limncea, 207-214. 
Outer lip reflected (land shell) Bulimus, 259-262. 
Inner lip reflected (land shell) Acicula, 398. 
Upper whorls sinistral Odostomia, 468-502. 

Height over treble the breadth 

Upper whorls sinistral Odostomia, 468-502. 
Subulate and polished Eulima, 461-466. 

Pyramidal 

Smooth or faintly ridged Aclis, 365-369. 
With bold spiral ridges TurriteUa, 452. 
With bold longitudinal ribs Scalaria, 360-364. 

Height less than double the breadth 
Peristome incomplete 

Shell thin, smooth, and glossy Jeffreysia, 435-437. 
Shell semi-globular, mouth semi-circular Neritina, 

356. 

Mouth horseshoe-shaped Bulimus (obscurus), 262. 
Pillar with fold Limncea, 207-214. 

Peristome complete 

Pillar with groove Lacuna, 392-396. 

Sinistral Physa, 227-229. 

Amber-coloured, mouth more than half the height of 

the shell Succinea, 313-317. 

Richly variegated and polished Phasianclla, 355. 
Inner lip thick, outer lip sharp Assiminec, 432, 433. 



72 TABULAR SCHEME. 

Shell thin- 
Outer lip thick Bithynia, 430, 431. 
Outer lip thin Hydrobia, 426-429. 

Shell moderately thick- 
Length over an inch Viviparus, 439, 440. 
Length under half-an-inch Rissoa, 400-424. 
Mouth nearly circular Cyclostoma, 397. 

Shell solid and smooth Barleeia, 425. 

Shell solid, heavy, and striated Littorina, 387-391 



Mouth grooved or with a canal 
Shell transparent Achatina, 312. 



Shell not transparent 
Shell convolute 
Spire hidden 
Outer lip plain 
Outer lip ribbed Cypraa, 457. 

Spire not hidden Marginella, 529. 

Shell fusiform with long narrow mouth 

Mouth smooth, outer lip notched Pleurotoina, 536-549. 

Mouth grooved Mangilia, 530-535. 

Mouth ridged, outer lip curved Lachesis, 510. 

Shell with a curved canal 

Pillar with fold at base Columbella, 511, 512. 
Pillar with tooth at base Nassa, 513-516. 
Pillar smooth 

Coarsely ribbed Buccinum, 517, 518. 

Finely striated Buccinopsis, 519. 

Shell with straight canal 

Canal covered Murex, 506, 507. 

Canal open 
Pillar smooth 

Canal long 

Shell measuring over an inch Fusus, 520-528. 

under an inchTrophon, 503-505, 
Canal short Purpura, 508, 509. 

Pillar folded or tuberculated 

Shell with disconnected varices Triton, 459, 460. 

Mouth with merely an indistinct notch 

Shell without longitudinal ribs, cavity at base of 

pillar Trichotropis, 380. 

Shell without ribs, globose and finely striated 
Torellia, 381. 



TABULAR SCHEME. 73 

This tabulation does not include the slugs, which can be sorted 
out as follows : 

Breathing hole near front of shield Geomalacus, 246. 
Breathing hole half way along shield Arion, 241-245. 
Breathing hole near back of shield 

Shield shagreened Amalia, 232, 233. 

Shield concentrically wrinkled Limax, 234-240. 

No breathing hole Onchidium, 318. 

The shell-bearing opisthobranchs also require a table to them- 
selves, the nudibranchs and other sea-slugs being sufficiently sorted 
out in the systematic chapters further on. 

Shell convolute 

Spire exposed Tornatinus, 551-557. 
Spire hidden Cylichna, 560-564. 

Shell incompletely convolute 

Pyriform, spirally striated Scaphander, 558, 559. 
Tumid, thin Accra, 568. 

Oval 

Spirally striated Action, 550. 
Spire involute Bulla, 565-567. 

Ear-shaped 

Thin and white Philine, 569-576. 
Thin, broad, horny, and glossy Aplysia, 577-579. 
Thin, broad, and iridescent Pleurobranchus, 580, 581. 



CHAPTER VII. 

IDENTIFICATION, 



SOME shells are recognisable at a glance. No one is likely to 
make a mistake with regard to Donax truncuhis and its square 
end, Donax polltus and its white ray, Isocardia and its curly beaks, 
the round Pectunculus, the fan-like Pinna, the ear-shaped Haliotis, or 
the only British cowry. With some*pf the genera, too, the forms 
are unmistakable. The armadillo-like Chitons, the long Solens, are 
as distinctive as can be wished, and it would require peculiar 
perversity to go wrong with regard to an lanthina or an Aporrhais. 
But with the majority of shells the distinguishing even of the genus 
is by no means so easy, and it can only be arrived at by some such 
system of elimination, conscious or unconscious, as we have adopted. 

To show how the foregoing keys are worked let us take a shell 
a bivalve to begin with. It is an every-day sort of specimen picked 
up on the beach, and its valves fell apart the instant they were 
touched,, as in dead shells they so often do. 

There is nothing peculiar about its back; there are no plates 
across where the hinge should be and no white fingers projecting 
inside from under the beaks ; in no way could it be said to resemble 
a Pholas. It is just an ordinary, straightaway shell. 

Its pallial line, which is about as visible as that made by a slug, 
is indented sharply, so that we can at once betake ourselves to 
Section C. The valves are equal in every respect; that gives us a 
further lift. The shell does not gape at all ; that takes us a long way 
on. All the ligament is outside, there are three teeth in both valves, 
the sinus is angular, and, therefore, the genus is Venus. But Venus 
what ? Turn to the chapter in which the genera are divided into 
species. Of Venus there are eight species. Three of these which 
belonged to the old genus Cytherea have the inside edge of the 
margin plain. An examination with the magnifying glass shows our 
specimen to be finely toothed, the pattern being that which can be 
made on pastry with a fork. The pattern does not extend along the 
posterior side, consequently the species is not ovata. It has not the 
fine striations and fan-like rays of gallina, nor the thick ribs and 
white mouth of verrucosa, nor the broad thin plates and mealy look 
of casina ; but it has flat concentric ribs and is pinkish with darker 
pink rays, and is, in fact, the only species leftfasciata and could 
have been at once identified by its size had we felt inclined to take 
it that way. 

74 



IDENTIFICATION. 75 

Yet one more to be introduced to by name. The shell is 
decidedly equivalve, but outrageously equilateral. It has no ears 
and only a sort of apology for a tooth. Its ligament is internal, so 
that if it is in the A division at all it must be in the last group. It 
has no radial ribs, and is, consequently, neither Crenella nor 
Modiolaria, but it has a pointed terminal beak, and the shelf inside 
under the beak distinguishes it as Dreissensia, the fresh water mussel, 
its neighbour in this tabulation, Mytilus, the salt water mussel, 
having no shelf. As it is represented by only one species we have 
no further to go. 

Let us have an instance which will take us beyond Division A. 
Here is a fine, large, well-shaped shell with a splendid hinge that 
ought to locate it at once, but does not. The shell is equivalve, 
without ears, with few teeth, inequilateral, and with ligament 
external; that is clearly neither an Anodonta nor a Unio. What is 
it ? Let us go on to Division B. Its grooves are concentric, its 
beaks are not twisted, its ligament is external, as we have seen, and 
it is conspicuous and is T partially overlapped in a groove. The anterior 
muscle scar does not project within the pallial line ; and thus we are 
left at Cyprina, the only British representative of the Cyprinida, 
which has only one species, islandica. 

And now let us deal with a specimen the other way round. 
Here is another shell. It has been brought into us with the animal 
in it. Being a bivalve we at once refer to the Pelecypoda to see 
to what order it belongs. A rough dissection shows us that the 
gill filaments are not divergent, that they are not parallel, that they 
are not loosely connected, but that they are bound into plates. This 
is enough to show that our specimen is one of the Eulamellibranchiata, 
and we have then to place it in its family. 

It is unfortunate that there should be so many families in the 
order, but after reading the notes as to some of the likely ones we 
try the last in alphabetical order and find that it answers fairly well. 
Its shell is regular and solid, its hinge has three large diverging 
cardinal teeth, its ligament is external, its adductor scars are oval 
and clear, and the pallial line has a particularly bold indentation. 
Evidently we have one of the Veneridae to deal with. 

But the Veneridae are represented in British waters by five 
genera; to which of them is it assignable ? To begin with, it has 
unmistakably three cardinal teeth in each valve. This relieves us 
of Lucinopsis, which has only two cardinals in the left valve. Neither 
of the six teeth is distinctly cloven, though there is just a trace of a 
beginning of division. This allows us to pass Circe, which has the 
posterior cardinal in the left valve cut in two. It has no well-marked 
concentric plates, only concentric ridges, and so it cannot be 
Venerupis, thus it must either be Venus or Tapes, and as Venus has 
an angular sinus in the pallial line, while this specimen has a 
distinctly marked line with a deep well-rounded bay, we have no 
difficulty in declaring its genus to be Tapes. 

We may as well find its species. It is concentrically striated, 
and consequently can be neither decussatus, in which the striations 
are radial and strong, nor pullastra, in which the striations are 



j6 IDENTIFICATION. 

radial and faint. It must be aureus or virginetts, and being rayed 
and spotted with reddish brown, instead of being streaked and 
blotched with brown and purple, it is evidently the latter. Tapes 
virgineus it is. Some reader may ask what is its other name ? The 
answer is that we do not know that it has another. 

Combining our information, we find that the shell is equivalve, 
inequilateral, yellowish in colour, rayed arid spotted with reddish 
brown, concentrically striated, the hinge having three cardinal teeth 
in each valve, the pallial line having a deep rounded sinus, and the 
muscular scars being oval. It would not take long to arrive at the 
genus by way of our key, for the indented pallial line takes us at 
once to the C division, the equivalve shell gives us another long step, 
the not gaping at either end another, and the ligament wholly 
external with the three teeth in both valves land us in either Tapes or 
Venus, which are separable by the shape of the indentations in the 
pallial line. 

Let us take another shell by the key. It is equivalve, but its 
valves are of a curious shape and prickly, and have a sort of plate 
on the back, with two arms stretching out into the interior from 
where the valves join. The shell, in fact, has dorsal pieces and 
apophyses, and the apophyses are long. As it is prickly all over, 
the genus is at once apparent as PJiolas. Taking it the other way 
round we find the Pholadidae to have a shell gaping at both ends 
without hinge or ligament, with one or more accessory dorsal pieces 
an internal apophysis from each beak cavity and the dorsal margin 
reflected over the beaks. There are three British genera in the family 
Xylophaga, with short apophyses, and the two others with long, 
and of these Plioladidea has prickly ridges in the fore part, and 
Pholas is prickly all over. Pholas, it will be found, has four species, 
one of which, dactylics, has four shields, the others having one, and 
of these Candida has radiating ribs, parva transverse ribs, and crisp at a 
longitudinal ribs. Pholadidea has only one species, and that has two 
dorsal shields, so that the prickliness is not the only guide. 

One more bivalve. Its pallial line is not indented, its shell is 
equivalve, it has no ears, and it has many teeth. This stops us 
early. If the hinge is straight, the genus is Area-, but the hinge is 
curved, then it is either Pectunculus, Leda, or Nucula. The shell is 
practically circular and the teeth are in two groups, one on each 
side of the beak ; that is the sign of Pectunculus and no other. 
Pectunculus it is, and turning to the species we find there is only one, 
glycimeris, and that the genus belongs to the Arcadae, which in their 
turn belong to the Filibranchiates, of which we have only three 
families Anomiidae, Arcadae, and Mytilidas. These three are 
strangely unlike : the Mytilidae being the mussels, the Anomiidae 
being the oyster-like mollusc with the large hole in the under valve 
through which the byssus passes, and the Arcadse being made up 
of Area, Pectunculus, and Limopsis, all of which have the many- 
toothed hinge. 

Now let us take a gastropod, and let it be a fair-sized specimen 
with plenty of ribs and striations. Look at its mouth : is there any 



IDENTIFICATION. 77 

sign of a groove or canal in its periphery ? If so, we can at once 
take a long stride onwards, and ask if it is transparent ; which it is 
not. And so it has both a groove and a canal, as it happens, and it 
is decidedly opaque, being, in fact, rather thick and heavy. Is it 
convolute ; that is, does its outer lip turn in so as to make a long 
narrow mouth as in the cowry ? No. Is it fusiform, with a long 
and narrow mouth ? No ; neither has it a curved canal, but the 
canal is covered over and is like a tunnel through the shell. That is 
enough ; the genus is Murex, and if the canal had been continued 
down a long tube, the genus would still be Murex. 

Let us take another genus, often confused with it, and answering 
all our questions in the same way up to here. The canal is not 
covered but open, and is decidedly short. Hence the genus is 
Purpum, and as the ridges are alternately large and small the 
species is lapillus, although sometimes the ridges of that species are 
all of the same size ; and it has the teeth in the throat, which most, 
but not all, of its representatives have, for lapillus has so many 
variations that only three of its varieties have been thought worth 
mentioning. 

Here is another, in which the margin of the mouth is without a 
groove or canal. The shell is neither tubular, nor globular, nor ear- 
shaped, nor cap-shaped, nor is the mouth toothed. It is not coiled 
flat, and that clears us of four genera ; but it is a raised spiral. The 
pillar does not project beyond its mouth, its apex is not divided into 
two. nor is it broken off short, and its outer lip is not slit, so we can 
pass half-a-dozen more genera. Its height is not less than its 
breadth, that clears away seven more genera. But its height is less 
than double its breadth, and that leaves us among four genera, from 
which it can be separated by its having a fold in its pillar. The 
genus is Limnaa, and a reference to the index of geneia will show 
that the species is stagnalis. 

Yet one more. The margin of the mouth without a groove or 
canal, no teeth, the shell not coiled flat, the shell a raised spiral, the 
height less than double the breadth, peristome complete, the pillar 
without a groove, dextral, not amber-coloured, not richly variegated 
and polished, not with the inner lip thick and the outer lip sharp, 
the shell not thin but moderately thick, the mouth nearly circular. 
At last I The genus is Cyclostoma, of which there is but one species, 
elegans, found mostly on the chalk and rarely in other limestone 
districts, and it is worth knowing as being one of the two British 
land shells that have an operculum. 



CHAPTER VIII. 

GLOSSARY, 



Aberrant differing from the type. Abnormal differing from the rule. 

Abranchiate without gills. Abrade to wear away. 

Abyssal pertaining to the deep sea. Acephalous headless. 

Acetabula the suckers of a cephalopod. Aculeated ending in a point. 

Acuminate taper pointed. Acute forming a sharp angle or point. 

Adductor the muscle which draws together the valves of a bivalve. 

Albino -the white variety of any species. Alliaceous smelling of garlic. 

Amorphous of no regular form. 

Amphineura an order of the Gastropoda, having the nerves on both sides. 

AmpullaceOUS in the form of a flask. 

Androgynous having the sexes united in each individual. 

AngUlated having angles. Anterior the front or forepart. 

Aperture the mouth of a shell. Apex the top of the spire. 

Apical belonging to the apex. Articulated jointed. 

Ascoglossa a sub-order of Opisthobranchs having the worn-out teeth not dropping off 

but retained in a special sac. 

Attenuated gradually tapering to a point. Auriculated shaped like an ear. 
Axis the pillar the whorls of a shell are twisted round. 
AzygObranchiate having but one gill, and not a pair equal in size as if they were the 

arms of a yoke. 

Bidentate having two teeth. Bifid cleft into two parts. 
Bilateral with two symmetrical sides. Bilobed with two lobes. 
Bivalve composed of two plates or valves. 

BOSS the umbo or beak of a bivalve shell. Brackish moderately salt. 
Branchia a respiratory organ adapted to breathe air dissolved in water ; a gill. 
Branchial belonging to the gills. Branchiate possessing gills. 
Buccal connected with the mouth. 
BysSUS the silky filaments by which certain bivalves attach themselves to foreign 

substances. 

CadUCOUS falling off at certain seasons. Calcareous limy. 
CanaliCUlated made like a groove. Cancellated cross-barred. 
Caperate -wrinkled. Cardinal belonging to the hinge. 
Carinated keeled. Cephalic belonging to the head. 
Cinereous ash-coloured. CirrhUS a filamentary tentacle. 
CladOhepatiC having a branching liver. 
Clausilium a shelly plate attached to the pillar by an elastic ligament, and protecting 

the entrance to the shell. 

Clavate club-shaped. Columella the pillar round which the whorls wind. 
Compressed flattened. Concave rounded inwards. 

7 8 



GLOSSARY. 79 

Concentric having the same centre. ConcMfera an old term for the bivalves. 

Constricted narrowed. Convex rounded outwards. 

Cordate shaped like a heart. Coriaceous -leathery. Corneous horny. 

Costate ribbed. Crenate -scalloped. Crenulated finely toothed. 

Cruciate in the form of a cross. 

Crura the basal part of a brachiopod's arms, of which the loop is a further develop- 
ment. 

Cuneate shaped like a wedge. 

DeCidUOUS falling off. Decollated having lost the apex of the shell. 

Dentated toothed. Denticle a small tooth. Depressed pressed downwards. 

Dextral right-handed. Dextrorse turned to the right. 

Diaphanous transparent , Dilated Expanded. 

Dimyary having two adductor muscles. 

DiOtOCardiac having a heart with two auricles. Dioecious having the sexes distinct. 

DiSCOldal resembling a disc. Diverging radiating. 

Dorsal belonging to the back. DorsibrancMate with gills attached to the back. 

DocoglOSSa a section of the Diotocardia in which the radula possesses only a few strong 
teeth arranged in rows compared to beams. 

Edentulous toothless. Emarginate notched. Ensiform sword-shaped. 

Entire uninterrupted by breaks or notches. Epidermis the outer skin. 

Epiphragm the hardened mucus with which the mouth of some univalve shells is closed. 

Epipodium- a fold occurring on the upper edge of the foot. 

Equilateral having sides of equal length. 

Eqiltvalve having valves of equal size. Excoriated worn away. 

EuthyneurOUS having the nerves Straight. 

Falciform process that which serves as a point of attachment for the muscles of the 
foot and viscera. 

Fasciculated arranged in bundles. Ferruginous containing or resembling iron. 

Filament a thread. 

Filibranchiate having the gill filaments unconnected except by surface cilia. 

Filiform like a thread. Flexuous curved. FlUViatile living in rivers. 

Foliaceous leaflike. Foliated composed of thin laminae. 

Fossetta the pit in which the internal ligament is contained. FUSCOUS dark brown. 

Fusiform tapering towards both ends. GibbOUS swollen. 

Glabrous smooth. Globose almost spherical. 

Globular almost globose. Granulated covered with grains. 

Guard the sheath protecting the phragmoccne of certain cephalopods. 

GymnoglOSSa a section of the Monotocardia, having no radula. 

HaliotO id ear-shaped . 

Heteromyary having the anterior adductor muscle smaller than the posterior adductor. 

Hispid bristly. HolOhepatiC having an unbranched liver. 

HolOStomata univalve shells with mouths entire. 

Hyaline glassy. Imbricated overlapping. Inflected bent inwards. 

Inoperculate -without an operculum. Intersected cut across. 

Intorted twisted inwards. Involute rolled inwards. 

Iridescent rainbow-like in colour. 

Isomyary having the adductor muscles of equal size. 

Lamella ted having layers like plates. 

Lamellibranchiata having gills like leaves or plates. 

Lamelliform shaped like a thin plate. Lanceolate shaped like a lance. 



OO GLOSSARY. 

Lenticular shaped like a bi-convex lens. 

Ligament the band uniting the two valves of pelecypods. 

Lunate shaped like a crescent. 

Maculated spotted. Malacology the science which treats of the mollusca. 

Mantle the external integument of the mollusca. 

Mesopodium the middle portion of the foot. 

Metapodium the posterior portion of the foot. Moniliform beaded. 

Monoecious having the sexes united in each individual. 

Monomyary having one adductor muscle. 

MonotOCardiac having a heart with one auricle. Mucronate abruptly pointed. 

Muricated covered with prickles. 

Myophore the shelf to which in certain species of bivalves the internal ligament 

is attached. 

Nacreous pearly. Nautiloid resembling the pearly nautilus in shape. 
Normal usual ; according to rule. 

Nudibraucbiate having the breathing organs exposed. 
Nucleated having a nucleus. 

Oblique -slanting. Oblong greater in length than in width. 
Oboval oval, with the broad end towards the apex of the shell. 
Obtuse blunt. Odontophore the lingual ribVm or radula. 
Operculated having an operculum. 

Operculum the plate which closes the mouth in many univalves. 
OpiSChobranchiate having the breathing organs behind the heart. 
Osphradium the organ of smell, consisting of a modified portion of epithelium. 
OtOCyst the organ of hearing, consisting of a small vesicle containing fluid secretion. 
Otolith a concretion suspended in the otocyst. Ovate egg-shaped. 
Oviparous producing eggs. Ovoid nearly elliptical. 
OVQViviparous producing offspring by hatching the eggs, and retaining the young for 

a time within the parent's body. 

Pallial belonging to the mantle. Parapodium the lateral edge of the foot. 
Paucispiral having only a few whorls. Pectinated toothed like a comb. 
Pectinibranchiate having comb-like gills. Pelagic -pertaining to the ocean. 
Periphery the widest part of the body whorl. 

PeriOStracum the outer covering of the shell. Peristome the margin of the mouth. 
Pinnate feather-shaped. Plicata folded like a fan. 
Polyplacophora a sub-order of amphineurans, containing those whose shells have 

many plates. 

Propodium the fore part of the foot. 

PrOSObranchiate having the breathing organ in front of the heart. 
ProtObrancbiate having the simplest form of gill. 
PtenOglOSSa a section of the Monotocardia, having a radula in which the outer teeth 

are largest. 

Pteropoda the class of mollusca having winged feet. 
Pulmonate breathing by means of lungs. 

Pulmonobranchiate having gills like lungs. Pyriform pear-shaped. 
RaclliglOSSa a section of the Monotocardia, having the teeth in sharp ridges. 
Radula the chitinous band in the mouth and throat of gastropods. 
Recurved bent backwards. Reticulated being of the pattern of network. 
RhipidOglOSSa a section of the Diotocardia, having fan-shaped teeth. 
Rotund rounded in outline. RufOUB of a reddish colour. 



GLOSSARY.- 8 1 

Kllgose -wrinkled. 

Scalariform shaped like a ladder. 

Septibranchiate having gills modified into a muscular partition through which the 

divisions of the pallial chamber communicate by means of narrow orifices. 
Serrate like the teeth of a saw. 

Sessile not supported on a stalk. Setaceous like bristles. 
Shagreen covered with granules like the skin of certain sharks and rays. 
Sinistral to the left hand. Sinuate curved in and out. Sinuous wavy. 
Siphon a tube. Specific pertaining to species. 
Spire the assemblage of whorls excepting the body whorl. 
StreptoneurouS having the nerves twisted. 

Striated marked with slender lines like threads. Sub rather ; not quite. 
Sulcate furrowed. Suture the line of junction between the whorls. 
Tsenioglossa a section of the Monotocardia, having the radula of a compact ribbon 

shape. 

Tectibranchiate having the breathing organ covered by the mantle. 
Terrestrial living on land and not in water. 

Tessellated patterned like a chess-board. Testaceous shelly. 
ToxoglOSSa a section of the Monotocardia, having no teeth but marginals, so that the 

radula resembles an arrow. 

Translucent transmitting light, but not transparent. Truncate cut off short. 
Tubercle a pimple. Tumid-swollen. 
Turbinated shaped like a top. Turreted rising in steps. 
Ulate shaped like an awl. Umbilicated having an umbilicus. 
Umbilicus the hole at the base of the axis in univalve shells. UmbO the beak. 
Ungulated shaped like a finger-nail. Unilateral on one side only. 
VariX a raised band or ridge. VentriCOSO -swollen. 

Vermiform -shaped like a worm. VerruCOSe warty. VisCOUS sticky. 
Vitreous glassy. Viviparous Producing young in a living and perfect state. 
Volution a whorl. 

Whorl a single revolution of the spire in a univalve shell. 
Zy go branchiate having the gills in pairs as if yoked. 



CHAPTER IX. 

CLASSES, ORDERS, AND SUB-ORDERS, 



THE mollusca are divided into four classes : 

1. Cephalopoda (head-footed), having the foot in the form of 

arms around the head. 

2. Gastropoda (belly-footed), having the foot beneath the body. 

3. Scaphopoda (spade-footed), "having the foot more or less in 

the shape of a spade. 

4. Pelecypoda (axe-footed), having the foot more or less in the 

shape of an axe. 

The Cephalopoda, as stated in Chapter III., are divided into 
two orders : 

1. Dibranchiata, those with two gills. 

2. Tetrabranchiata, those with four gills. 

The Gastropoda are divided into four orders, the first con- 
taining such forms as have a multivalve shell and are bilaterally 
symmetrical, the other three being comprised of those which have 
the shell univalve or absent, and are asymmetrical. Thus we have: 

Shell multivalve 

1. Amphineura. 

Shell univalve or absent 

2. Prosobranchiata gills in front of heart, visceral loop 

twisted, one pair of tentacles, shell generally operculated ; 
dioecious. 

3. Opisthobranchiata gills behind heart, visceral loop not 

twisted and shell not operculated (except in Act&ori), foot 
prolonged into lateral epipodia or into parapodia ; 
monoecious, 

4. Pulmonata air breathing, visceral loop not twisted and 

shell not operculated, two pairs of tentacles ; monoecious. 
82 



CLASSES, ORDERS, AND SUB-ORDERS. 83 

The Amphineura have been divided into two sub-orders Poly- 
placophora and Aplacophora of which the latter consists entirely 
of vermiform species not represented in Britain. 

The Prosobranchiata are divided into two sub-orders : 

1. Diotocardia heart usually with 2 auricles; gills 2, bi- 

pectinate. 

2. Monotocardia heart with i auricle ; gill i, monopectinate. 

The Opisthobranchiata have been further divided into four 
sub -orders 

1. Tectibranchiata right gill present, shell enveloped in folds 

of mantle and foot. 

2. Pteropoda foot modified into fins, animal externally sym- 

metrical and internally asymmetrical, with or without 
mantle fold or shell. 

3. Ascoglossa gills both absent, shell absent; old teeth not 

lost but preserved in a special askos or sac. 

4. Nudibranchiata gills modified or absent, shell absent, 

mantle fold rudimentary. 

The Pulmonata have been divided into two sub-orders : 

1. Basommatophora eyes at base of tentacles7~~ 

2. Stylommatophora eyes at tip of tentacles. 

The Scaphopoda have a plain tubular shell, occasionally tumid, 
but generally pointed and slightly curved, as if it were a model 
elephant's tusk, and they form an interesting but small class 
containing only three genera. 

The Pelecypoda the bivalves, conchifera, or lainellibrarichiata, 
as they used to be called are divided into five orders : 

1. Protobranchiata gill filaments divergent. 

2. Filibranchiata gill filaments parallel. 

3. Pseudolamellibranchiata gill filaments loosely connected, 

anterior adductor muscle aborted, so that they have but one 
muscle instead of two like the others. 

4. Eulamellibranchiata gill filaments bound into plates, mantle 

edges united at one or more places. 

5. Septibranchiata gills modified into a muscular septum with 

symmetrical orifices, mantle edge united in three places. 



84 CLASSES, ORDERS, AND SUB-ORDERS. 

Of these five orders, two have been further divided. The sub- 
orders of the Filibranchiata are : 

1 . Anomiacea one aorta ; anterior adductor small ; shell 

with plug perforating right valve. 

2. Arcacas two aortas ; both adductors large ; shell without plug. 

3. Mytilacea one aorta; anterior adductor small; shell with- 

out plug. 

The sub-orders of the Eulamellibranchiata include the great 
majority of the British bivalves, but they are not easily distinguish- 
able, from description owing to the many exceptions that have to be 
provided for. We have, therefore, not used them in this system of 
identification. They are, with the families represented in our fauna. 

1. Submytilacea. 

Carditidas, Astartidae, Cyprinidse, Unionidas, Dreissensiidas, 
Lucinidae, Erycinidse, Galeommidae, Cyraenidae. 

2. Tellinacea. 

Telliiiidas, Scrobiculariidae, Donacidae, Mactridas. 

3. Veneracea. 

Veneridae, Petricolidae. 

4. Cardiacea. 

Cardiidse. 

5. Myacea. 

Psammobiidag, Myidae, Solenidas, Glycimeridae, Gastro- 
chcenidae. 

6. Pholadacea. 

Pholadidae, Teredinidae. 

7. Anatinacea. 

Pandoridae, Lyonsiidae, Anatinidae. 



CHAPTER X. 

ORDERS AND FAMILIES, 



FOR the purposes of easy reference, we have here adopted 
alphabetical order, and not systematic order, as in the pre- 
ceding chapter. The descriptions of the families are such as are, 
it is hoped, sufficient to distinguish them among their British repre- 
sentatives. The numbers, as in all the chapters, refer to the 
coloured plates. 

Amphineura. (GASTROPODA.) Plate xvi. Nos. 190 to 200. 



. Shell somewhat resembling that of a wood-louse, and com- 
posed of eight overlapping valves surrounded and kept in position by 
a muscular girdle, external portion of the valves largely composed 
of chitin. Chiton, 190 to 200. 



Eulamellibranehiata. (PELECYPODA.) Plates v. to xv. 

Nos. 49 to 178. 

ANATINID/E. Shell thin, oval or oblong, gaping on each side, and trun- 
cated at posterior end ; internal cartilage contained in a receptacle 
beneath the beak in each valve ; hinge with free crescentic ossicle ; 
muscular scars small and irregular, pallial scar narrowly but deeply 
sinuated ; a fourth pallial orifice. Thracia, 174 to 178. 

ASTARTIDJE. Shell triangular, thick, concentrically grooved or furrowed; 
ligament external ; hinge with three cardinals in each valve, and with 
two laterals in each valve that are ridge-like and obscure. Astarte, 
50 to 52. 

CARDIKUE. Shell equi valve and heart-shaped, with radiating ribs, and 
often with concentric foliations forming scales and spines and 
tubercles ; beaks prominent ; ligament external ; the two adductor 
scars oval and distinct, pallial scar entire ; no byssus ; foot long and 
sickle-shaped. Cardium, 129 to 138. 

CARDITID^. Shell equivalve and inequilateral ; ligament external ; 
muscular scars large, round, and deep, pallial scar entire ; hinge with 
a lateral tooth in both valves, one double cardinal tooth in the right 
valve, and two cardinals in the left. Cyamium, 49. 

/** 85 



86 ORDERS AND FAMILIES. 

CYPRINID^E. Shell equi valve, thick, concentrically furrowed or striated; 
beaks often spiral ; ligament external ; hinge with two or three 
cardinal teeth in each valve and usually a posterior tooth ; muscular 
scars oval and distinct, pallial scar entire. Cyprina, 53 ; and 
Isocardia, 54. 

CYPR^NID^E. Shell suborbicular and thin ; hinge with cardinal and 
lateral teeth ; ligament external and placed on posterior side of hinge ; 
foot large and tongue-shaped ; no byssus ; one siphon or two siphons 
more or less united. Spharium, 81 to 84; and Pisidium, 85 to 89. 

DONACID^S. Shell equivalve, solid, smooth, sub-triangular, or wedge- 
shaped, inside margin with notches ; ligament external. Donax, 
104 to 106. 

DREISSENSIID^E. Shell mytiliform, rising to a ridge in the middle of each 
valve, equivalve, inequilateral, ventricose, beaks anterior ; below the 
beak a triangular shelf for the anterior muscle ; ligament internal ; 
hinge toothless or with minute cardinals ; anterior adductor impression 
small, posterior large ; shell attached by a byssus. Dreissensia, 60. 

ERYCINID^. Shell equivalve, inequilateral, thin ; mantle edges with three 
apertures ; cartilage internal ; beak calyciform ; foot long, broad, 
and with a byssus. Kellia, 73, 74 ; Lasaa, 75 ; Lepton, 76 to 79. 

GALEOMMID^E. Shell equilateral, thin ; mantle reflected over a consider- 
able part of the valves ; mantle edges with three apertures ; foot long, 
broad and with a byssus. Galeomma, 80. 

GASTROCHCENID^E. Shell equivalve, gaping; with thin, edentulous valves 
occasionally cemented to a calcareous tube or sheath. The tube is 
club-shaped, long and slender ; it is covered with adhering particles 
of sand, and divided off by a partition into two portions, the anterior 
end containing the shell, the posterior, or narrower end, the siphons. 
Gastrochana t 159. 

GLYCIMERID^E. Shell more or less equivalve, rhomboidal, gaping and 
obliquely truncated at posterior end ; hinge, toothless or with two 
weak cardinals, having an upright ledge to support the ligament, which 
is external ; pallial scar far in and with a deep sinus ; adductor scars 
large and conspicuous. Saxicava, 156, 157 ; Panopcea, 158. 

LUCINID.E. Shell equivalve, occasionally toothless ; pallial scar entire ; 
adductor scars conspicuous, that of the anterior muscle being long 
and falling within the uninterrupted pallial line. Lucina, 61, 62 ; 
Loripes, 63, 64 ; Diplodonta, 65 ; Axinus, 66 to 68 ; Montacuta, 69 to 72. 

LYONSIID^. Shell inequivalve, oblong, nearly equilateral ; teeth usually 
absent, right valve more convex than the left ; hinge with a free plate 
or ossicle, covering the ligament which is in an internal groove. 
Lyonsia, 173. 

MACTRID^E. Shell equivalve and triangular; hinge with ligament on 
larger side of shell in an internal groove, the other portion external ; 
a forked cardinal tooth in the left valve fitting into a branching tooth 
in the right valve; muscular scars deep and distinct. Amphidesma, 
107; and Mactra, 108 to 112. 



ORDERS AND FAMILIES. 87 

MYIDJE. Shell inequi valve, oblong, and gaping widely on the posterior 
side, and often, but more narrowly, on the anterior side also ; pallial 
line broad and deeply sinuated, muscular scars large and distinct ; 
ligament on a prominent shelf ; periostracum wrinkled and extensive. 
My a, 143 to 145 ; Corbula, 146 ; Lutmria, 147, 148. 

PANDORID^:. Shell inequivalve, semilunar, pearly, and gaping at posterior 
end, which is flexuous and elongated ; ligament entirely internal, long 
and oblique and often with calcareous ossicle ; pallial line entire or 
with slight sinus. Pandora, 172. 

PETRICOLID^:. Shell oval or elongated, thin, gaping slightly behind ; 
hinge with three teeth in each valve, the external often obsolete ; 
pallial sinus deep and well marked. Petricola, 128. 

PHOLADHXE. Shell gaping at both ends without hinge or ligament ; one 
or more accessory dorsal pieces ; an internal apophysis from the beak 
cavity ; dorsal margin partly reflected over the beaks. Pholas, 160 to 
163 ; Pholadidea, 164 ; Xylophaga, 165. 

PSAMMOBIID^. Shell nearly equilateral, long oval, compressed, striated 
concentrically and longitudinally, posterior side somewhat truncate 
and gaping ; ligament external and prominent ; two cardinal teeth in 
each valve, the posterior one in the left valve being small and set 
obliquely, the others being cloven ; pallial sinus deep. Psammobia, 
139 to 142. 

SCROBICULARIID.E. Shell equivalve, white, gaping at posterior end ; beaks 
turned towards posterior side, and almost contiguous ; hinge teeth 
weak, and consisting of two small cardinals in right valve and one in 
the left valve ; ligament in an internal cavity. Scrobicularia, 99 to 103. 

SOLENID^;. Shell equivalve, narrow, long, and gaping at both ends ; 
hinge strengthened inside by a ridge ; teeth usually two and three, the 
cardinals being shaped like thorns ; ligament external; beaks flattened. 
Sohcurtus, 149 and 150; Ceratisolen, 151 ; Solen, 152 to 155. 

TELLINID^. Shell equivalve, compressed ; ligament external, and on 
shortest side of shell ; beaks incurved and nearly straight ; siphons 
separated, slender, and very long ; mantle widely open in front, and 
with fringed margin ; foot and labial palpi large ; adductor scars far 
apart; pallial impression deeply sinuated. Tellina, 90 to 97; 
Gastrana, 98. 

TEREDINID^. Shell small, continued into a long, calcareous tube ; valves 
deeply notched ; an internal apophysis; siphons long, and ending with 
two calcareous pallets. Teredo, 166 to 171. 



. Shell equivalve, oblong, inequilateral, pearly within; large 
external ligament ; anterior hinge teeth thick and striated, posterior 
teeth often wanting ; all teeth occasionally rudimentary. Unio, 55 to 
57, and Anodonta, 58, 59. 



Shell regular and solid ; hinge usually with three large, 
diverging cardinal teeth, laterals variable ; ligament external ; adductor 
scars oval and distinct, pallial line deeply sinuated. Circe, 113 ; Vemts, 
114 to 121 ; Lucinopsis, 122 ; Tapes l 123 to 126; Venernpis t 127. 



ORDERS AND FAMILIES. 



Filibranehiata. (PELECYPODA.) Plates i. and ii. Nos. 9 to 29. 



. Shell irregularly oyster-shaped, having no teeth, and being 
attached to rocks and stones by a calcified byssus which passes 
through a large hole near the hinge. Anomia, g, 10. 

ARCADE. Shell with valves equal ; hinge long with many serrate teeth ; 
muscular impressions nearly equal ; foot large, bent, and grooved ; 
mantle edge with composite eyes. Area, n to 15 ; Pectunculus, 16 ; 
Limopsis, 17, 18. 



^E. Shell with valves equal, but inequilateral ; beaks incurved ; 
anterior muscular impression small, posterior impression large ; byssus 
well developed ; ligament long and narrow and in a groove. Mytilus, 
ig to 23 ; Crenella, 24, 25 ; Modiolaria, 26 to 29. 



Opisthobranchiata. (GASTROPODA.) Plates xxx. to xxxiii. 
Nos. 550 to 611. 

ASCOGLOSSA. Plate xxxi. Nos. 586 to 590. 

ELYSIID.E. Body depressed, head rather elevated ; no branchiae ; no 
shell ; sides of body dilated into two large wings. Elysia, 588. 



.^:. Body depressed; no branchiae; no shell; cerata in several 
rows. Hermcea, 586 ; Alderia, 587. 

LIMAPONTIID^E. Body slug-like; no branchiae or other appendages; no 
shell. Limapontia, 589 ; Actceonia, 590. 

NUDIBRANCHIATA. Plates xxxi., xxxii. Nos. 591 to 6n. 



Body slug-like ; head with tentacles ; dorsal area with rows 
of cerata usually containing sting cells. JEolis, 591 ; Embktonia, 592 ; 
Fiona, 593; Proctonotus, 594; Antiopa, 595; Hero, 596. 

DENDRONOTID^;. Body slug-like, rather compressed; two rows of 
arborescent cerata ; no tentacles ; pointed margin, with arborescent 
papillae. Dendronotus, 599. 



. Branchiae of a circle or semicircle of pinnate leaves, united at 
base. Doris, 603. 

DOTONID^. Body slug-like ; two rows of cerata, each ceras surrounded 
by a ring of tubercles. Doto, 598. 

GONIODORID^:. Body oval; branchiae multifoliate, and in the shape of a 
horseshoe. Goniodoris, 609; Ancttla,6io; Idalia, 611. 

LOMANOTID.E. Body slug-like; one row of small cerata; no tentacles. 
Lomanotus, 597. 

PLEUROPHYLLIDIID^. Body covered by arched shield, with lateral angles 
prolonged ; mantle pale reddish brown, with small black specks. 
Pleurophyllidia, 601. 

POLYCERID/E. Body slug-like ; branchiae not retractile ; tentacles simple, 
usually surrounding the posterior end. Polycera, 604 ; JEgirus, 605 ; 
Triopa, 606 ; Thecacera, 607 ; Crimora, 608. 



ORDERS AND FAMILIES. 89 

SCYLL/EID.E. Body oblong, compressed ; two large, foliated cerata, with 
branchial appendages on the inner side ; no tentacles. Scyllaa, 600. 

TRITONIID.E. Body long ; two rows of unequal arborescent cerata, 
Tntonia, 602. 

PTEROPODA. Plate xxx. Nos. 583 to 585. 

CAVOLINIID^. Fins large, shell a cone, angular or circular, very thin, 
ridged lengthwise or spinous ; five ridges in front and one at back. 

Clio, 584. 

CLIONID^E. Body long, angulated behind, no shell. Clione, 585. 

LIMACINID/E. Fins very large, shell spiral, thin and fragile, translucent ; 
whorls five in number, tumid, the last more than half the shell ; 
umbilicus small. Spirialis, 583. 

TECTIBRANCHIATA. Plate xxx. Nos. 550 to 582. 



;. Shell spiral, solid, entirely covering the animal ; spirally 
striated; spire generally prominent, pillar with ridge-like fold con- 
tinued within the spire; suture well marked. Action, 550. 



. Shell arched, flattened, slightly convolute at smaller end 
which is thickened by a projection ; mouth extending whole length of 
shell ; spire short and terminal. Aplysia, 577 to 579. 

BULLION. Shell convolute internal or partly internal ; spire hidden or 
nearly so, mostly short ; mouth extending the whole length of the 
shell or nearly so. Bulla, 565 to 567 ; Acera, 568. 



. Shell internal, thin, slightly spiral ; spire small and truncated; 
mouth large and open ; pillar sharp-edged, flexuous and visible 
throughout. Philine, 569 to 576. 

PLEUROBRANCHID^. Dorsal region protected by a covering or shell, 
Pleurobranchus, 580 to 581. 

RUNCINID^;. No shell. Runcina, 582. 

SCAPHANDRID.E. Shell oval, spirally striated, external, covering all or 
nearly all the animal ; spire hidden ; mouth extending whole length 
of shell, contracted behind, expanded in front ; pillar smooth and 
with a blunt edge. Scaphander, 558, 559 ; and CyUchna, 560 to 564. 

TORNATINID^;. Shell cylindrical or globular, covering the animal, spire 
truncated ; whorls keeled ; mouth extending whole length of shell, 
expanding in front; small fold at base of pillar. Tornatinus, 551 to 557. 



PrOSObranchiata. (GASTROPODA.) Plates xxi. to xxix. 
Nos. 319 to 549. 

ACICULID^. Shell small, cylindrical, thin, with long blunt spire; mouth 
oval; umbilicus straight ; operculum horny. Acicula, 398. 



Shell patelliform ; crown close to front margin; internal 
border distinctly marked. Tectura, 319. G 



QO ORDERS AND FAMILIES. 

ADEORBID^;. Shell small, porcellanous, depressed, circular or ear-shaped; 
umbilicus wide, operculum horny ; spire depressed, mouth obliquely 
rhombic, angulated above and emarginate below. Adeorbis, 438. 

APORRHAID^;. Shell with outer lip dilated ; spire turreted and tapering ; 
no umbilicus, operculum pear-shaped. Aporrhais, 455, 456. 

ASSIMINEID^:. Shell small, conoidal ; spire short ; mouth roundish oval, 
inner lip thick, outer lip sharp ; operculum horny, nucleus on inner 
side of mouth. Assiminea, 432, 433. 

BUCCINID.E. Shell fusiform, thick, ridged; spire short, body whorl 

large ; mouth oval, pillar twisted ; canal short and curved back ; 

operculum horny and never spiral. Bnccinum, 517, 518 ; 
Buccinopsis, 519. 

C.ECID^E. Shell a cylinder curved or straight, the spire being lost when 
young ; operculum horny, circular with a central nucleus. Cacum, 
453- 454- 

CAPULID.^E. Shell patelliform, spire small; generally an internal plate to 
which the adductors are attached;, no opsrculam. Capulus, 382; 
Calyptraa, 383 ; Crepidula, 384. 

CERITHIIDJE. Shell long, spire tapsring to a fine point ; whorls many, 
generally tuberculate, varicose or spiny ; mouth small, sometimes 
strongly channelled ; groove at base short and recurved ; no umbilicus. 
Cerithium, 443 to 446 ; Cerithiopsis, 447 to 451. 

COLUMBELLID^E. Shell small, fusiform, mouth narrow, canal short and 
deeply notched, outer lip thick and sinuated ; pillar with one fold at 
base; operculum horny. Columbella, 511, 512. 

CONID^. -Shell fusiform ; spire tapsring or turreted ; mouth narrow and 
oblong; outer lip notched at or near suture, pillar smooth, canal 
nearly straight. Mangilia, 530 to 535 ; Pleurotoma, 536 to 549. 

CYCLOSTOMATID^E, Shell spiral ; spire elevated ; mouth circular or nearly 
so ; umbilicus small and narrow ; operculum solid. Cyclostoma, 397. 

CYCLOSTREMATID^E. Shell discoidal, cancellated ; mouth nearly circular ; 
umbilicus wide ; operculum spiral, calcareous. Cyclostrema, 335 to 337. 

CYPR^ID.E. Shell convolute, solid, spire hidden ; mouth long, straight, 
narrow, toothed at sides, channelled at ends, outer lip folding inwards. 
Cypma, 457 ; Ovula, 458. 

EULIMIDJE. Shell subulate, small and long, with many whorls : spire 
finely tapering ; mouth pyriform ; operculum horny, with nucleus on 
inner side. Eulima, 461 to 466 ; Stilifer, 467. 

FASCIOLARIID^E. Shell fusiform, spire long and tapering; throat and 
pillar smooth ; pillar curved ; canal often very long ; operculum 
horny; no umbilicus. Fusus, 520 to 528. 

FISSURELLID/E. Shell patelliform, elevated or depressed, with a slit in the 
crown, in front of the crown, or on the anterior margin. Fissurella, 
326, 327 ; Puncturella, 328 ; and Emarginula, 329 to 332. 



ORDERS AND FAMILIES. gi 

HALIOTID.E. Shell ear-shape ; spire flattened ; mouth large and pearly; 
outer lip perforated, the perforations being successively filled up when 
no longer required for the protrusion of the tentacles of the mantle. 
Haliotis, 333. 

HOMALOGYRID/E. Shell a small, flat coil, with involute spire ; whorls 
angulated; operculum with few whorls and a central nucleus. 
Homalogyra, 385, 386. 

HYDROBIID^;. Shell conical, small, smooth ; mouth entire ; an umbilical 
cleft ; eyes at the base of the tentacles. Hydrobia, 426 to 429 ; Bithynia, 
430, 431- 

IANTHINID^;. Shell heliciform, violet in colour, thin, translucent, fragile ; 
whorls few and ventricose ; mouth four-sided. lanthina, 357 to 359. 

JEFFREYSIID.E. Shell minute, translucent, smooth, and glossy ; mouth 
oval or roundish ; operculum with marginal nucleus divided by an 
inner rib. Jeffrey$ia, 435 to 437. 

LAMELLARIID/E. Shell more or less internal ; ear-shaped or cap-shaped, 
thin, pellucid, and fragile ; spire very small, mouth large, no oper- 
culum. Lamellaria, 377; Velutina, 378, 379. 

LEPETID^;. Shell limpet - shaped, crown central or nearly central. 
Lepeta, 322 ; Propilidium, 323. 

LITTORINID^E. Shell strong and never pearly ; pillar thickened ; mouth 
rounded and entire ; operculum horny, thin, ear-shaped, nucleus 
excentrical. Littorina, 387 to 391 ; Lacuna, 392 to 396. 

MARGINELLID^E. Shell oval, polished ; mouth truncated, narrow, 
channelled at base only, and nearly as long as shell ; outer lip 
thickened, pillar with few oblique folds. Marginclla, 529. 

MURICID/E. Shell having a straight anterior canal, and being oblong and 
solid and tuberculate, spiny or varicose ; spire produced ; mouth 
oval ; pillar not twisted. Trophon, 503 to 505 ; Murex, 506, 507 ; Pur- 
pura, 508, 509 ; Lachesis, 510. 

NASSID^.- Sheiroblong, small ; spire turreted; canal short and abrupt; 
outer lip thickened, often toothed ; operculum horny. Nassa, 513 
to 516. 

NATICID/E. Shell globular, thick, smooth, few whorls, and small spire ; 
outer lip simple; large umbilicus; operculum horny and calcareous. 
Natica, 370 to 376. 

NERITID/E. Shell globular, thick ; spire small ; mouth semi-lunate, side 
near pillar being expanded ; operculum calcareous, with prominent 
apophyses on interior face, one of which locks behind the lip of the 
pillar. Neretina, 356. 

PATELLID^E. Shell conical with apex turned forwards; mouth forming 
entire base of cone. Patella, 324 ; Helcion, 325. 

PLEUROTOMARIIDJE. Shell trochiform with sinus band extending nearly 
to apex ; umbilicus deep ; operculum horny, circular and multi-spiral, 
nucleus central. Scissurella, 334. 



92 ORDERS AND FAMILIES. 

PYRAMIDELLID^;. Shell small, conical, turreted, apical whorls sinistral ; 
mouth small, angulated, channelled, outer lip thin ; operculum horny, 
ear-shaped, nucleus excentrical. Odostomia, 468 to 502. 

RISSOID^E. Shell small, oblong or oval, white or horny ; spire usually 
long ; mouth oval or trumpet-shaped, angulated above and slightly 
expanded below ; operculum horny. Rissoa, 400 to 424. 

SCALARIID.'E. Shell long, turreted, with transverse ribs; mouth round; 
operculum horny and few whorled. Scalaria, 360 to 364 ; Aclis, 
365 to 369. 

SKENEID^E. Shell small, circular; spire much depressed or involute; 
mouth round; operculum horny, round and spiral. Skenea, 434. 

TRICHOTROPID^. Shell conical, last whorl large ; spire erect ; mouth 
grooved within at the base ; operculum blunt and claw-shaped. 
Trichotropis, 380 ; Torellia, 381. 

TRITONID^. Shell thick, outer lip inflected and thickened ; whorls 
strengthened lengthwise by varicose ribs; spire bluntly pointed; 
outer lip and pillar folded or tuberculate ; canal straight ; operculum 
horny, nucleus at outer base of mouth. Triton, 459, 460. 

TROCHID^;. Shell nacreous, pyramidal with a nearly flat base, whorls 
many, flat and striated; pillar twisted; operculum horny. Trochiis, 
338 to 354. 

TRUNCATELLID^E. Shell cylindrical, minute; spire truncated, whorls 
striated transversely ; mouth oval ; operculum horny, sub-spiral, ear- 
shaped. Truncatella, 399. 

TURBINIDJE. Shell bulimoid, polished, richly coloured; whorls convex; 
mouth oval, not pearly; operculum shelly. Phasianella, 355. 

TURRITELLIDJE. Shell pyramidal and long, upper part divided off when 
disused ; whorls many, slowly enlarging, spirally ribbsd or striated; 
mouth small, round or inclined to be square ; operculum horny, 
rather solid, puckered obliquely, nucleus central. Turritella, 452. 

VALVATID^;. Shell turbinate or discoidal ; spire short and symmetrical; 
mouth rounded and entire ; umbilicated ; operculated ; operculum 
horny, nucleus central. Valvata, 441, 442. 

VIVIPARID^;. Shell turbinate with long symmetrical spire, whorls rounded, 
mouth oval, operculum horny and irregularly concentric. Vivipams, 
439, 440. 



ProtObranehiata. (PELECYPODA.) Plate i. Nos. i to 8. 



. Gills small ; labial pulpi very large ; mantle free all round ; 
foot long ; shell like a small nut with many serrate teeth, often with 
posterior side produced. Genera, Nucula, i to 4 ; and Leda, 5 to 8. 



ORDERS AND FAMILIES. 93 

Pseudolamellibranehiata. (PELECYPODA.) Plates iii. to v. 

Nos. 30 to 48. 

AVICULID^E. Shell oblique and winged; with long straight dorsal margin; 
posterior adductor nearly central ; anterior adductor, when present, 
leaving impression within the beak. Avicula, 30 ; Pinna, 31. 

LIMID^E. Shell nearly equivalve, eared; cartilage external; muscular 
scar on one side. Lima, 44 to 48. 

OSTREID^;. Shell irregular, attached by the left valve; a single adductor; 
hinge without teeth ; margins occasionally notched ; cartilage internal 
and horizontal on the hinge line; no foot; mantle lobes free all round. 
Ostrea, 32. 



. Shell equilateral, with unequal wings at beak ; inequivalve ; 
some with the right valve convex and the left flat ; cartilage internal 
and in a cavity beneath the beaks. Pecten, 33 to 43. 



Pulmonata. (GASTROPODA.) Plate xvii. to xx. Nos. 201 to 318. 

AURICOLID^E. Shell spiral, conoidal ; mouth toothed; umbilicus indistinct 
or absent ; tentacles two, not retractile, eyes generally at base. 
Carychium, 201 ; Melampus, 202, 203. 

HELICID;E. Animal terrestrial ; shell spiral, globose or coil-shaped ; with 
or without umbilicus ; tentacles four, retractile ; eyes at the tip of 
the upper pair which are the longer. Vitrina, 247 ; Zonites, 248 to 
258 ; Bulimus, 259 to 262 ; Helix, 263 to 287. 



Animal terrestrial ; shell internal, placed beneath the mantle, 
rudimentary or shield shaped ; tentacles four, cylindrical, retractile ; 
eyes at the tip of the dorsal pair. Amalia, 232, 233 ; Limax, 234 to 
240 ; Avion, 241 to 245 ; Geomalacus, 246. 



. Shell spiral, hood-shaped, or coil-shaped; thin; horn- 
coloured ; mouth without teeth, lip sharp ; pulmonary sac protected 
by an external lobe ; tentacles two, not retractile ; eyes at base. 
Ancylus, 205, 206 ; Limn#a, 207 to 214 ; Planorbis, 215 to 226. 

ONCHIDIID^E. No shell; animal oval and slug-like; two tentacles, 
retractile, with eyes at their tips ; a thick mantle over the dorsal 
region, covered with tubercles, having eyes identical in type with 
those of the vertebrata ; foot much narrower than mantle. Onchidium, 
318. 

OTINID^. Shell ear-shaped and minute, spire short, apex introverted, 
mouth large, outer lip plain and sharp, no operculum ; tentacles two, 
not retractile ; eyes at base. Otina, 204. 

PHYSIOS. Shell sinistral, lustrous, thin, without operculum ; mantle 
covering part of the shell ; tentacles two, not retractile ; eyes at base. 
Physa, 227 to 229. 

PUPID.E. Shell cylindrical or oblong, occasionally furnished with internal 
lamellae ; many narrow whorls, last whorl no broader than the pre- 
ceding ; mouth generally with one or more teeth. Pupa, 288 to 291 ; 
Vertigo, 292 to 302 ; Balea, 303 ; Clausilia, 304 to 309 ; Cochlicopa, 
310, 311. 



94 ORDERS AND FAMILIES. 

STENOGYRID^. Shell long, cylindrical, thin, translucent ; spire long, 
whorls rapidly increasing in size, mouth notched. Achatina, 312. 

SUCCINEID.^. Shell oval or oblong, thin ; spire short, last whorl large, 
mouth obliquely oval ; tentacles four, retractile. Succinea, 313 to 317. 

TEST ACELLID^;. Animal terrestrial and slug-like ; shell rudimentary, ear- 
shaped and external, and borne at the posterior end of the body, two 
pairs of retractile tentacles, eyes at the tip of the upper pair. 
Testacella, 230, 231. 



Septibranehiata. (PELECYPODA.) Plate xv. Nos. 179 to 183. 

POROMYID^;. Shell small, inequivalve, pearly within ; cartilage in a 
triangular cavity under each beak ; hinge strong, toothless or not, 
and having occasionally an ossicle ; foot long and narrow ; siphons 
short, unequal, separate and surrounded by a tentacular fringe. 
Poromya, 179; Ne#ra, 180 to 183. 



FAMILIES AND GENERA. 95 



CHAPTER XI. 

FAMILIES AND GENERA, 



T N this the families are arranged alphabetically, and the chief 
-*- distinguishing marks of their constituent genera noted and 
compared. The orders are given as facilitating reference to 
the preceding chapter. 

Aeieulidse. (PROSOBRANCHIATA.) Plate xxiii, 
Acicula, 398. 

Acmseidse. (PROSOBRANCHIATA,) Plate xxi. 
Tectura, 319. 

Aetseonidse. (OPISTHOBRANCHIATA.) Plate xxx. 
Action, 550. 

Adeorbidse. (PROSOBRANCIIIATA.) Plate xxiv. 
Adeorbis, 438. 

^Eolididse. (OPISTHOBRANCHIATA.) Plate xxxi. 

JEolh, body limaciform, branchial processes in transverse rows, 
tentacles four two dorsal, two oral, 591. ' 

Embletonia, tentacles two, 592. 
Fiona, tentacles four, sub-dorsal, 593. 

Proctonotus, body depressed; tentacles four two dorsal, two 
oral, 594. 

Antiopa, body ovoid, depressed, 595. 

Hero, body limaciform, branchial processes in one series, 596, 

Anatinidse. (EULAMELLIBRANCHIATA.) Plate xv. 
Thracia, 174. 

AnomiidSB. (FILIBRANCHIATA.) Plate i. 
Anomici, g, 10. 

Aplysiidse. (OPISTHOBRANCHIATA.) Plate xxx. 
Aplysia. 577"579. 



g6 FAMILIES AND GENERA. 

Aporrhaidse. (PROSOBRANCHIATA.) Plate xxv. 
Aporrhais, 455, 456. 

Areadae. (FILIBRANCHIATA.) Plate i. 
Ana, hinge straight, 11-15. 

Pectunculus, shell orbicular, nearly equilateral ; hinge semi- 
circular, striated ligamental area, 16. 

Limopsis, hinge with two curved series of transverse teeth and 
triangular cartridge pit in the middle, 17, 18. 

Assimineidse. (PROSOBRANCHIATA.) Plate xxiv. 
Assiminea, 432, 433. 

Astartidse. (EULAMELLIBRANCHIATA.) Plate v. 
Astarte, 50-52. 

AuriCUlidse. (PULMONATA.) Plate xvii. 

Carychium, umbilicus an oblique sttt, 201. 
Melampus, no umbilicus, 202, 203. 

AviCUlidse. (PSEUDOLAMELLIBRANCHIATA.) Plate iii. 
Avicula, shell winged ; hinge with teeth, 30. 
Pinna, shell triangular, not winged ; hinge without teeth, 31. 

Bueeinidse. (PROSOBRANCHIATA.) Plate xxvii. 

Buccinum, coarsely grooved, operculum lamellar, with nucleus on 

outer side of mouth, 517, 518. 
Buccinopsis, finely striated, operculum with nucleus on inner side 

of mouth, 519. 

Bullidse. (OPISTHOBRANCHIATA.) Plate xxx. 

Acera, mouth extending nearly the length of the shell, 568. 
Bulla, mouth extending the whole length of the shell, 565-567. 

CDBCidse. (PROSOBRANCHIATA.) Plate xxv. 
Ccscum, 453, 454. 

Capulidse. (PROSOBRANCHIATA.) Plate xxiii. 

Capulus, shell cap-shaped, no internal plate, 382. 
Calyptrcea, shell conical, with internal plate, 383. 
Crepidula, shell slipper-shaped, with septum covering half the 
mouth, 384. 

Cardiidse. (EULAMELLIBRANCHIATA.) Plate xi. 
Cardium, 129-138. 



FAMILIES AND GENERA. 97 

. (EULAMELLIBRANCHIATA.) Plate v. 
Cy ami urn, 49. 

Cavoliniidse. (OPISTHOBRANCHIATA.) Plate xxx. 
Clio, 584. 

CePithiidSB. (PROSOBRANCHIATA.) Plate xxiv. 

Cerithium, mouth small, with a groove at its base, short and 

recurved, 443-446. 
Cerithiopsis, mouth small, with a canal, short, truncated, and 

straight, 447-45 1 - 

Chitonidse. (AMPHINEURA.) Plate xvi. 
Chiton, 190-200. 

ClioniddB. (OPISTHOBRANCHIATA.) Plate xxx. 
Clione, 585. 

Columbellidse. (PROSOBRANCHIATA.) Plate xxvi. 
Colwnbella, 511, 512. 

Conidse. (PROSOBRANCHIATA.) Plate xxix. 

Mangilia, inside of mouth grooved, outer lip notched at its junction 
with periphery, 530-535. 

Pleurotoma, inside of mouth smooth, outer lip notched below its 
junction with periphery, 536-549. 

CyelOStomatidse. (PROSOBRANCHIATA.) Plate xxiii. 
Cyclostoma, 397. 

Cyelostrematidse. (PROSOBRANCHIATA.) Plate xxi. 
Cyclostrema, 335-337. 

Cypraeidse. (PROSOBRANCHIATA.) Plate xxv. 
Cyprcea, outer lip ribbed, 457. 
Ovula, outer lip plain, 458. 

CyprinidSB. (EULAMELLIBRANCHIATA.) Plate v. 

Cyprina, beak not spiral, 3 cardinal teeth, 53. 
Isocardia, beak spiral, 2 cardinal teeth, 54. 

. (EULAMELLIBRANCHIATA.) Plate vii. 

Spkarium, shell nearly equilateral, with two siphons, beak near 
middle of dorsal margin, 81-84. 

Pisidium, shell inequilateral, with one siphon, beak near anterior 
end, 85-89. 



9 FAMILIES AND GENERA. 

Dendronotidse. (OPISTHOBRANCHIATA.) Plate xxxii. 
Dendronotus, 599. 

DentaliidSB. (SCAPHOPODA.) Plate xv. 

Cadulus, shell spindle-shaped, 185, 186. 

Dentalium, shell tusk-like, with or without slit, 187-189. 

Siphonodentalium, shell tusk-like, with 4 notches at base, 184. 

DonaeidSB, (EULAMELLIBRANCHIATA.) Plate viii. 
Donax, 104-106. 

Dorididse. (OPISTHOBRANCHIATA.) Plate xxxiii. 
Doris, 603. 

DotonidSB. (OPISTHOBRANCHIATA.) Plate xxxii. 

Doto, 598. 

DPCissensiidae. (EULAMELLIBRANCHIATA.) Plate vii 
Drelssensia, 60. 

ElysiidSB. (OPISTHOBRANCHIATA.) Plate xxxi. 

Elysia, 588. 

Eryeinidse. (EULAMELLIBRANCHIATA.) Plate vii. 

Lepton, a cardinal and two strong lateral teeth in each valve, 

76-79. 

Lascea, a small cardinal in the left valve and two strong lateral 
teeth in each valve, 75. 

Kellia, a thick, erect cardinal in the left valve, and in each valve 
two strong laminar teeth which are partly cardinal and partly 
lateral, 73, 74. 

EulimidSB. (PROSOBRANCHIATA.) Plate xxv. 

Eulima, shell subulate, tapering to a regular point, 461-466. 
Stilifer, shell globose, spire divided into two parts, 467. 

Fasciolafiidse. (PROSOBRANCHIATA.) Plates xxvii., xxviii., xxix. 
Fusus, 520-528. 

FiSSUrellidSB. (PROSOBRANCHIATA.) Plate xxi. 
Fissiirelhi, slit at the crown, 326, 327. 
Puncturella, slit in front of the crown, 328. 
Emarginula, slit on anterior margin, 329-332. 



(EULAMELLIBRANCHIATA.) Plate vii. 
Galeomma, So. 



FAMILIES AND GENERA. 

GastPOChcenidse. (EULAMELLIBRANCHIATA.) Plate xiv. 
Gastrochcena, 159. 



(EuLAMELLiBRANtniATA.) Plate xiv. 

Saxicava, pallial scar interrupted or broken up into separate 
spots, 156, 157. 

Panopaa, pallial scar entire, 158. 

GoniodOPidSB. (OPISTHOBRANCHIATA.) Plate xxxiii. 

Goniodoris, oral tentacles flattened and angular, 609. 

Ancula, oral tentacles of two tubercular processes on the sides of 
the head, 6to. 

Idalia, no oral tentacles, 6n. 

Haliotidse. (PROSOBRANCHIATA.) Plate xxi. 
Haliotis, 333. 

Helieidse. (PULMONATA.) Plates xix., xx. 

Vitrina, shell greenish, subglobular, thin, vitreous, no umbilicus, 
247. 

Zonites, shell orbicular, thin, mouth oblique, umbilicus more or 
less distinct, 248-258. 

Bullmns, shell long and spiral, mouth oval, umbilicus small, 
259-262. 

Helix, shell globular or flattened, mouth circular or oval, outer 
lip generally thick and having a rib, sometimes reflected and 
toothed, 263-287. 

Hermseidse. (OPISTHOBRANCHIATA.) Plate xxxi. 
Herman, tentacles 2, body ovate, 586. 
Alderia, tentacles none or rudimentary, body tapering, 587. 

HomalOgyPidse. (PROSOBRANCHIATA.) Plate xxiii. 

Homalogyra, 385, 386. 

HydPObiidse. (PROSOBRANCHIATA.) Plate xxiv. 

Hydrobia, eyes on tubercles, operculum horny, 426-429. 
Bithynia, eyes sessile, operculum shelly, 430, 431. 

lanthinidse. (PROSOBRANCHIATA.) Plate xxii. 
lanthina, 357. 

Jeffpeysiidse. (PROSOBRANCHIATA.) Plate xxiv. 
Je/reysia, 435-437- 

LamellaPiidse. (PROSOBRANCHIATA.) Plate xxiii. 

LameUavia, shell internal, ear-shaped, very thin, 377, 
Vehitina, shell external, cap-shaped, spire small, suture deep, 
37 8 . 379- 



100 FAMILIES AND GENERA. 

Lepetidse. (PROSOBRANCHIATA.) Plate xxi. 
Lepeta, crown almost central, 322. 
Propilidium, crown central, a shell-like, triangular plate, 323. 

Limaeidse. (PULMONATA.) Plate xviii. 

Amalia, breathing hole in posterior half of shield, shield sha- 
greened, 232, 233. 

Limax, breathing hole in posterior half of shield, shield concen- 
trically wrinkled, 234-240. 

Avion, breathing hole half-way along shield, shell of loose 
calcareous grains, covered by hinder part of shield, 241-245. 

Geomalacus, breathing hole near front edge of shield, shell ungui- 
form, imbedded in the shield, 246. 

Limaeinidse. (OPISTHOBRANCHIATA.) Plate xxx. 
Spirialis, 583. 

Limapontiidse. (OPISTHOBRANCHIATA.) * Plate xxxi. 

Limapontia, no tentacles, 589. 
Acteeonia, two tentacles, 590. 

Limidse. (PSEUDOLAMELLIBRANCHIATA.) Plate v. 
Lima, 44-48. 



(PULMONATA.) Plate xvii. 
Ancylus, shell hood-shaped, 205, 206. 
Limnaa, shell spiral, 207-214. 
Planorbis, shell a flat coil, 215-226. 

LittOPinidSB. (PROSOBRANCHIATA.) Plate xxiii. 

Lacuna, pillar channelled or grooved, 392-396. 
Littorina, pillar not channelled or grooved, 387-391. 

Lomanotidse. (OPISTHOBRANCHIATA.) Plate xxxii. 
Lomanotus, 597. 

Lueinidse. (EULAMELLIBRANCHIATA.) Plate vii. 

Lucina, shell circular, bsaks depressed, 61, 62. 
Loripes, shell circular, lateral teeth remote and indistinct, 63, 64. 
Diplodonta, ligament wholly external, 65. 
Ax inns, shell globular, posterior side angulated, 66-68. 
Montacuta, shell minute, thin, oblong, anterior side the longer, 
ligament internal, 69-72. 



FAMILIES AND GENERA. IOI 

Lyonsiidse. (EDLAMELLIBRANCHIATA.) Plate xv. 
Lyonsia, 173. 

MaetridSB. (EULAMELLIBRANCHIATA.) Plate ix. 

Amphidesma, teeth of unequal size in both valves, 107. 
Mactra, teeth of unequal size in right valve only, 108-112. 

MarglnellidSB. (PROSOBRANCHIATA.) Plate xxix. 
Marginella, 529. 

Murieidae (PROSOBRANCHIATA.) Plate xxvi. 

Trophon, canal open throughout, outer lip not notched within, 

503-505- 
Lachesis, canal open throughout, outer lip notched within, canal 

short and wide, 510. 

Murex, canal covered over, 506, 507. 

Ptoi'pura, pillar flattened, sloping inwards with a sharp edge, 
508, 509. 

MyidSB. (EULAMELLIBRANCHIATA.) Plate xii. 

My a, upright spoon-shaped cavity for cartilage, under beak of 
right valve, 143-145. 

Corbula, right valve overlapping left, 146. 

Lutraria, hinge plate projecting in the middle, 147,^48. 

Mytilidae. (FILIBRANCHIATA.) Plate ii. 

Crenella, shell striated all over; hinge with an upright tooth, 
24, 25. 

Modiolaria, shell striated only at ends, 26-29. 

Mytilus, shell oblong triangular, ending in a point and having its 
two extremities equal, pedal muscular impressions, two in each 
valve, small, simple, close to the adductors, 19-23. 

NassidcB. (PROSOBRANCHIATA.) Plate xxvi. 
Nassa, 513-516. 

Naticidse. (PROSOBRANCHIATA.) Plate xxiii. 

Natica, 370-376. 

NePitidse. (PROSOBRANCHIATA.) Plate xxii. 
Neritina, 356. 

Nueulidse. (PROTOBRANCHIATA.) Plate i. 

Nucula, shell trigonal, lunule cordate, pallial line entire, 1-4. 
Leda, shell with posterior side produced, lunule lanceolate, pallial 
line sinuated, 5-8. 



IO2 FAMILIES AND GENERA. 

Onehidiidse, (PULMONATA.) Plate xx. 
Onchidium, 318. 

Ostreidae. (PSEUDOLAMELLIBRANCHIATA.) Plate iii. 
Ostrea, 32. 

Otinidse. (PULMONATA.) Plate xvii. 
Otina, 204. 

Pandoridse. (EULAMELLIBRANCHIATA.) Plate xv. 
Pandora, 172. 

Patellidse. (PROSOBRANCHIATA.) Plate xxi. 

Patella, shell conical ; crown near centre, 324. 
Helcion, shell cap-shaped ; crown near margin, 325. 

PeCtinidSB. (PSEUDOLAMELLIBRANCHIA*TCA.) Plates iii., iv. 
Pecten, 33 -43- 

Petrieolidse. (EULAMELLIBRANCHIATA.) Plate x. 

Petricola, 128. 

Philinidse. (OPISTHOBRANCHIATA.) Plate xxx. 
Philine, 569-576. 

Pholadidse. (EULAMELLIBRANCHIATA.) Plate xiv. 

Pholas, apophyses long and partly hidden within the junction ; 
shell prickly all over, 160-163. 

Pholadidea, apophyses long and partly hidden within the junction ; 
anterior part covered with prickly ridges ; posterior end with 
horny cup attached, 164. 

Xylophaga, apophyses short and prominent, 165. 

Physidse. (PULMONATA.) Plate xvii. 
Physa, 227-229. 

Pletirobranehidse. (OPISTHOBRANCHIATA.) Plate xxx. 
Pleurobranchus, 580, 581, 

PleUFOphyllidiidse. (OPISTHOBRANCHIATA.) Plate xxxii. 
Pkurophyllidia, 601. 

PleUPOtomariidSB. (PROSOBRANCHIATA.) Plate xxi. 
Scissurella, 334. 



FAMILIES AND GENERA. 103 

Polyeeridse. (OPISTHOBRANCHIATA.) Plate xxxiii. 

Polycera, dorsal tentacles laminated and non-retractile, 604. 
SEgirus, dorsal tentacles linear and retractile, oral indistinct, 605. 
Triopa, dorsal tentacles laminated and retractile, oral cylindrical, 

606. 

Thecaccra, dorsal tentacles laminated and retractile, oral none, 607. 
Crimora, dorsal tentacles laminated and retractile, oral tuber- 
cular, 608. 

PoromyidSB. (EULAMELLIBRANCHIATA.) Plate xv. 
Poromya, shell roundish oval, 179. 

Neara, shell fig-shaped, posterior end being twisted and produced, 
180-183. 

Psammobiidse. (EULAMELLIBRANCHIATA.) Plate xii. 
Psammobia, 139-142. 

PupidSB (PULMON.ATA). Plate xx. 

Pupa, mouth oval or lunate, 288-291. 

Vertigo, mouth more or less angular, 292-302. 

Balca, shell sinistral, mouth ovate, 303. 

Clausilia, shell sinistral, mouth with clausilium, 304-309. 

Cochlicopa, mouth pyriform, 310, 311. 

PyramidellidSB. (PROSOBRANCHIATA.) Plate xxvi. 
Odostomia 468-502. 

RisSOidcG (PROSOBRANCHIATA.) Plate xxiv. 
Barleeia, colour red, 425. 
Rissoa, colour not red, 400-424. 

Runeinidse. (OPISTHOBRANCHIATA.) Plate xxx. 
Runcina, 582. 

ScalariidSB. (PROSOBRANCHIATA.) Plate xxii. 

Scalaria, shell turreted, longitudinally ridged, mouth almost 
round, 360-364. 

Aclis, shell pyramidal, smooth or sculptured, mouth oval, outer 
lip thin, 365-369. 

Seaphandridse. (OPISTHOBRANCHIATA.) Plate xxx. 
Scaphander, shell pear-shaped or oval, 558, 559. 
Cylichna, shell cylindrical, 560-564. 



104 FAMILIES AND GENERA. 

SePObiCUlariidSB (EULAMELLIBRANCHIATA.) Plate viii. 
Scrobicularia, 99-103. 

SeyllJBidSB. (OPISTHOBRANCHIATA.) Plate xxxii. 

Scyllaa, 600. 

Skeneidse. (PROSOBRANCHIATA.) Plate xxiv. 
Skenea, 434. 

Solenidse (EULAMELLIBRANCHIATA.) Plate xiii. 

Solecurtus, two cardinals in right valve, pallial scar with broad and 
shallow fold, 149, 150. 

Ceratisolen, hinge strengthened by a rib diverging obliquely from 
the beak in each valve towards the front margin, 151. 

Solen, pallial scar with a narrow sinus at the posterior extremity ; 
one cardinal in the right valve, 152-155. 

Stenogyridse. (PULMONATA.) Plate xx. 
Achatina, 312. 

Sueeineidse. (PULMONATA.) Plate xx. 
Succinea, 3 I 3-3*7- 

Tellinidse. (EULAMELLIBRANCHIATA.) Plates vii., viii. 

Tellina, two cardinals in each valve, those in the left valve of 
equal size, 90-97. 

Gastrana, two cardinals in each valve, those in the left valve of 
unequal size, one being minute, 98. 

Teredinidse. (EULAMELLIBRANCHIATA.) Plate xiv. 
Teredo, 166-171. 

Testaeellidae. (PULMONATA.) Plate xviii. 
Testacella,, 230, 231. 

Tornatinidse. (OPISTHOBRANCHIATA.) Plate xxx. 
Tornatiiius, 551-557. 

TroehidSB. (PROSOBRANCHIATA.) Plate xxii. 
Trochus, 338-354. 

TriehOtropidSB (PROSOBRANCHIATA.) Plate xxiii. 

Trichotropis, shell conical, spire long, apex pointed, 380. 
Torellia, shell globose, spire short, apex depressed, 381. 



FAMILIES AND GENERA. 105 

TritonidSB. (PROSOBRANCHIATA.) Plate xxv. 
Triton, 459, 460. 

Tritoniidse. (OPISTHOBRANCHIAIA.) Plate xxxii. 

Tritonia, 602. 

Truneatellidse. (PROSOBRANCHIATA.) Plate xxiii. 
Truncatella, 399. 

TllPbinidse. (PROSOBRANCHIATA.) Plate xxii. 
Phasianella, 355. 

TurritellidSB. (PROSOBRANCHIATA.) Plate xxv. 
Tiwritella, 452. 

Unionidse. (EULAMELLIBRANCHIATA.) Plates vi., vii. 

Unio, hinge with teeth strongly marked, lunule distinct, shell 
solid, 55-57. 

Anodonta, teeth rudimentary or absent, lunule indistinct, shell 
thin, 58, 59. 

Valvatidse. (PROSOBRANCHIATA.) Plate xxiv. 
Valvata, 441, 442. 

Veneridse. (EULAMELLIBRANCHIATA.) Plate ix. 

Circe, three cardinals in each valve, outer one in left valve on 
posterior side cloven in two, 113. 

Venus, pallial sinus angular, 114-121. 
Lucinopsis, two cardinals only in left valve, 122. 
Tapes, pallial sinus rounded, 123-126. 
Venerupis, shell oblong with concentric plates, 127. 

Viviparidse. (PROSOBRANCHIATA.) Plate xxv. 
Viviparus, 439, 440. 



CHAPTER Xll. 

GENERA AND SPECIES, 



THE distinctions between the genera having been given, we 
have here only such particulars as are needful for the 
identification of the species. In the concluding chapter the 
species will be arranged alphabetically. The dimensions are 
those of full-grown, well-developed examples. They do not in 
all cases agree with the illustrations, as most of the figures in 
the coloured plates were drawn from shells in the writer's 
possession, so as to give a better idea than usual of the sort of 
specimens a collector will meet with in an ordinary way. Where 
two dimensions are given, the first is the length. 

Acera. (BULLIDJE}. Plate xxx. 
568. biillata, ijin.xf in. whorls 6, ridged at the top. 

Achatina. (STENOGYRID&.} Plate xx. 

312. acicula, Jin. x^ in. whorls 5^, compressed and drawn out, 
rapidly increasing in size. 

Acicula. (ACICULID&). Plate xxiii. 
398. lincitta, Ji n - outer lip thin ; inner lip spread. 

Aclis (SCALARIIDM}. Plate xxii. 
369. gulsonte, 3*7 in. x^ in. whorls 6 or 7, shell smooth. 

366. ascaris, ^ in. x^ in. whorls 8 or 9, shell ridged. 
365. unica, % in. x-^ in. whorls 9 or 10, shell reticulated. 
368. walleri, in.x^ in. whorls 10, shell smooth. 

367, supranitida,m. x^in. whorls 12, shell smooth or ridged. 



Actseon. (ACTION ID JE). Plate xxx. 

colour pir 
body whorl. 

Actaeonia. (LIMAPONTIID&.) Plate xxxi 



550. tornatilis, f in. x in. colour pink, with three white bands on the 

'he 



corrugata, % in. head keeled at the sides. 

cocksii, in. head with a central black stripe. 

106 



GENERA AND SPECIES. IOy 

Adeorbis. (ADEORBID^E). Plate xxiv. 

438. sub-carinatus.&m.x ^in. shell trochiform, with a flattened base and 
a deep umbilicus. 



JEgirus. (POLYCERIDJE.) Plate xxxiii. 

605. punctihtcens, f in. purplish brown, sprinkled with white and 

brown. 

JEolis. (&OLIDIDM.) Plate xxxi. 

i. Body broad, branchial processes or papillae in many trans- 
verse rows. 
ii. Branchial processes clustered, dorsal tentacles laminated, 

angles of foot produced. 

iii. Dorsal tentacles smooth, angles of foot produced. 
iv. Dorsal tentacles with a bulbous swelling, 
v. Branchial processes in close set rows, 
vi. Branchial processes in distant rows, 
vii Branchial processes inflated, 
viii. Branchial processes in a single row on each side. 

i. Body broad, branchial processes or papillae in many transverse rows 
papillosa, 3 in. dorsal tentacles brown, tipped with white. 

glauca, if in. dorsal tentacles red, tipped with white. 

alderi, f in. dorsal tentacles bright yellow. 

ii. Branchial processes clustered ; dorsal tentacles laminated, angles 
of foot produced 

591. coronata, i in. dorsal tubercles yellowish, branchial pro- 

cesses with a white ring at the end. 

drwnmondi, i in. dorsal tentacles fawn coloured. 

punctata, i in. dorsal tentacles yellowish, branchial pro- 

cesses spotted with white. 

elegans, % in. dorsal tentacles drab, with white tips. 

iii. Dorsal tentacles smooth, angles of foot produced 

nifibranchiata, i in. body white ; branchial processes rosy, tipped 
with white. 

lineato, i in. body white ; branchial processes rosy, ringed 

with white. 

gracilis, Jin. body white; branchial processes orange, 

ringed with white. 

smaragdina, \ in. body white; branchial processes green, tipped 

with white. 

pellucida, f in. body white ; branchial processes red, tipped 

with white. 
landsburgi, % in. body violet. 



108 GENERA AND SPECIES. 

iv. Dorsal tentacles with a bulbous swelling 

alba, 2 in. body white, branchial processes dark brown 

and white. 

carnea, % in. body flesh coloured, branchial processes 

rosy. 
glaucoides, $ in. body white, branchial processes white, with 

yellow tips. 

v. Branchial processes in close set rows 

peachii, f in. body yellowish or flesh-coloured ; branchial 

processes fawn coloured, tipped with white. 

nassa, | in. body yellowish white ; branchial processes 

rose, tipped with white. 

stipata, J in. body yellowish green. 

angulata, f in. body pale orange. 

inornata, | in. body drab. 

concinna, % in. body white, 'tinged with buff; branchial pro- 

cesses purplish brown. 

olivacea, $ in. body yellowish white, with white spots. 

aurantiaca, J in. body buff. 

pustulata, % in. body white ; branchial processes pale orange, 

spotted with white. 

vi. Branchial processes in distant rows 

couchii, if in. body bluish black, spotted with white. 

amcena, J in. body greenish white ; branchial processes 

yellowish green or olive, spotted with white 
and brown. 

northumbrica, in. body greenish white ; branchial processes 
green, tipped with white. 

arenicola, f in. body white ; branchial processes green and 

yellow. 

glottensis, in. body greenish white ; branchial processes 

dark green, tipped with pale orange. 

cayulea, % in body pale green ; branchial processes green 

and blue, ringed with yellow and tipped 
with orange. 

viridis, in. body white, tinged with green ; branchial 

processes green, spotted with white. 

purpurasccns, i in. body pink. 

vii. Branchial processes inflated 

cingulata, f in. body white ; branchial processes with three 

brown bands. 

vittata, $ in. body drab ; branchial processes with brown 

bands, and pale yellow tips. 



GENERA AND SPECIES. IOQ 

picta, % in. body yellowish white ; branchial processes 

spotted with brown and white. 

tricolor, i in. body pale yellow ; branchial processes ringed 

with golden yellow. 

farrani, J in. body whitish, with orange spots. 

adelaida, in. body orange red. 

exigua, in. body yellowish white, mottled with brown. 

viii. Branchial processes in a single row on each side 

despecta, ^ n - body white, with narrow green line down 

back. 

Alderia. (HERM&ID&.) Plate xxxi. 
587. modesta, J in. branchial processes in six or seven diagonal 



Amphidesma. (MACTRIDJE.) Plate x. 
107. castaneum, in x in. margin closely toothed. 

Ancula. (GONIODORID&.} Plate xxxiii. 

610. cristata, % in. three tripinnate branchial plumes, with five 

linear appendages on each side. 



Ancylus. (LIMNjfclDJE.) Plate xvii. 

205. lacmtris, ^in. xjin. beak sharp, and turning to left, mouth 

oblong. 

206. fluviatilis, \ in. x J in. beak blunt and turning to right, mouth 

oval. 

Anodonta. (UNIONID^E.) Plates vi., vii. 

58. anatina, 3^ in. x 2 r 1 ir in. oval, beak at a third from anterior end, 
scars distinct. 

59- cygnea, 5^ in. x 2| in. oblong, beak at a fourth from anterior end, 
scars indistinct. 

Anomia. (ANOMIID&.) Plate i. 

9. ephippium,2%in.. x 2 Jin. hinge plate broad, muscular scar of upper 
valve with impressions of three inner por- 
tions of muscle, plug cylindrical and thick. 

10. patelliformis, ijin. x ijin. hinge plate narrow, muscular scar of 
upper valve with impressions of two 
inner portions of muscle, plug pear-shaped 
and thin. 

Antiopa. (MOLIDIDJE,'] Plate xxxi. 
595. cristata, ij in. dorsal tentacles yellow, with white tips. 

hyalina, in. dorsal tentacles grey, spotted with brown 

and white. 



no 



GENERA AND SPECIES. 



Aplysia. (APLYSIID^E.) Plate xxx. 

577. pnnctatii, 

578. depilans, 



579. melanopus, 



if in. mouth with the dorsal margin gently curved. 

2 in. mouth with the dorsal margin boldly 
rounded. 

2 in. semi-oval, with faint lines diverging from 
the straight margin. 



Aporrhais. (APORRFIAID&.) Plate xxv. 

455- pes-pelecani, if in. whorls 12, angulated ; the three processes 

of outer lip digitated. 

456. macandrca, i in. whorls 7 or 8, not angulated ; the four pro- 

cesses of outer lip narrow and spiked. 
Of 455 there is a variety albida which is whitish in colour. 

Area. (ARCAD/E.) Plate i. 

ii.pectiinculoides,m. x |in. posterior end broad, teeth seven or eight. 
15. nodulosa, in x ^ in. teeth less than ten, and oblique. 

12. obliqua, m - x T m - teeth less than twenty, and in two rows. 

13. lactca, in x ^ in. teeth less than thirty-five, and in one row. 

14. tetragona, i in. x in. teeth over forty. 

Arion. (LIMACID&.) Plate xviii. 

241. ater, 4 in. shell consisting of loosely aggregated cal- 

careous granules, tentacles black. 

242. bonrguignati, Jin. animal whitish grey, with lateral stripes. 

243 flavus, i in. shell white, opaque, wrinkled ; .animal pale 

grey, tentacles dark grey. 

244. hortensis, i^ in. shell granular, in an oval mass; animal with 

grey stripes. 

245. sub-fascus, J in. shell of isolated calcareous granules ; animal 

reddish, with two black stripes. 

Of 241 there are several varieties, such as aU> alette rail s l which is dark brown with white 
sides; bicolor, which i> dark brown with yellowish sides ; drapantaudi, which is dark 
red ; ma.rgina.ta, which is black with a yellow or grey fringe to the foot ; nigrescens, which 
is blackish with a red fringe to the foot ; pallescens, which is dirty white ; reticulata, which 
is reticulated with pale yellow and grey ; rufa, which is red or brown ; and sitccinea, which 
is arnber coloured. 

Of 244 there are three varieties, grisca, which is grey ; fasciata, which is grey, with 
black bands ; and rufescens, which is reddish, with black bands. 

Of 245 there is a variety aurantiaca which is bright orange. 

Assiminea. (ASSIMINEID^E.) Plate xxiv. 

432. grayana, if in. x ^ in. whorls 7, suture shallow. 

433. littorina, T x ff in. x T \ in. whorls 4, suture deep. 



Astarte. (ASTARTID&.) Plate v. 

50. sulcata, i in. x i^ in. shell ribbed, obtusely triangular. 

51. compressa, J in. x in. shell ribbed, acutely triangular. 



GENERA AND SPECIES. I* 1 

52. triangularis, Jin. x Jin. smooth, or with indistinct striations, acutely 
triangular. 




small, and markedly triangular ; and truncata, which has the front margin nearly straight. 
Of 51 there are three varieties globosa, which is fairly circular, with regular ribs, 
striata, which is closely ribbed, and nana, which is smaller, and occasionally smooth. 

Avicula. (AVICULID&.) Plate iii. 

30. himndo, if x 3 in. shell elliptical and winged, upper valve 
the larger. 

Axinus. (LUCINID&.) Plate vii. 

66. flexuosus, ^ in. x in. white, ligament visible outside. 

67. croulinensis, J in. x ^ in. white, ligament not visible outside. 

68. ferruginosus.^in. x Jin. reddish brown. 

Of 66 there is a variety f>olyona. which has a few longitudinal ridges. 

Balea. (PUPIDJE.) Plate xx. 
303. perversa, | in. left handed, with a shining top whorl. 

There is a variety of this viridula which is greenish white, the typical colour being 
yellowish brown. 

Barleeia. (RISSOID&.) Plate xxiv. 

425. rubra, f in. whorls, with a dark band, 5^, gradually 

enlarging, operculum dark red. 

The general colour is dark red or tawny, but there is a variety unifasciata which is 
whitish, and there is another /0///Vfo which is pinkish white. 

Bithynia. (HYDROBIID&.) Plate xxiv. 

430. leachii, \ in. whorls 5, mouth nearly round. 

431. tentaculata, J in. whorls 6, mouth oval, angular above. 

Of 430 there is only one variety <?/<?vzte -which is smaller, with a longer spire. 
Of the varieties of 431 ventricosa. is white with swollen whorls, decollata. has lost if- 
upper whorls, and exccmata has rounded whorls and a deep suture. 

Buccinopsis. (BUCCINIDJE.} Plate xxvii. 
519. dalei, ij in. colour ivory white. 

Variety eburnea shell thinner with the spire longer. 

Buccimim. (BUCCINIDjE.) Plate xxvii. 

517. undatum, 3^ in. outer lip sinuated deeply, inner lip broad. 

518. humphreysianum, if in. outer lip sinuated slightly or not at all, 

inner lip imperceptible. 

Of Buccinum there are many vaiieties, depending on the kind of ground on which the 
animal lives, and many of them are as worthy of a name of their own as those to which 
names have been given. Some are stout, some slender, some smoother, some smaller, some 
more fully coloured, and, of course, there is the usual albino. The monstrosities are inter- 
esting ; one has ridges on the upper part of each whorl, another has the body whorl com- 
pressed and lengthened, so as to give the shell the shape of a volute, one has a long spire, and 
some have been found with two or even three opercula. 



112 GENERA AND SPECIES. 

Bulimus. (HELICIDSE.) Plate xix. 

Spire long ; outer lip thin and unreflected 

259. acutus, f in. whorls 8 or 9, umbilicus shallow. 

Spire blunt ; outer lip thick and reflected 

260. goodallii, in. whorls 7 or 8, body whorl occupying a third 

of shell. 

261. montanus, in. whorls 6J or 7j, umbilicus oblique and deep. 

262. obscurns, Jin. whorls 6J, umbilicus narrow not deep, shell 

golden brown, thin and translucent. 

Of 259 there are seven varieties elongata, with a slender spire; inflata, which is stouter ; 
bizona, which has two dark bands on the body whorl ; strigata, which has white ribs and 
brownish streaks ; articulata, which has white ribs and violet streaks ; nigrescens, which is 
violet brown, paler round the umbilicus ; and alba, whicli is white. Of 261 there is but one 
variety, albino., which is also entirely white, and of 262 there is also a white variety which 
is known as albinos. 

Bulla. (BULLIDJE.) Plate xxx. 

565. hydatis, i in. outer lip projecting beyond crown, crown 

not perforated. 

567. utriculus, J in. outer lip projecting beyond crown, crown 

perforated. 

566. elegans, J in. outer lip not projecting beyond the crown. 

Globosa is a variety of of 565 ; it is smaller, globular, and cream colour, with no greenish 
yellow. Oblonga is a variety of 567 ; it is smaller and more cylindrical. 

Cadulus. (DENT A LI I D^.} Plate xv. 

185. subfusiformis, ^ in. spindle-shaped and narrow, base with curved 

notch on each side. 

186. jeffreysii, Jin. spindle-shaped and dilated, outer curve 

constricted near the end. 

Csecum. (CJECID&.) Plate xxv. 

453. trachea, in. shell ribbed. 

454. glabrum, ^ in. shell smooth. 

Calyptrsea. (CAPULIDsE.) Plate xxiii. 

383. chinensis, f in. shell as broad as long, white, but generally 

yellowish at the point. 

Capulus. (CAPULID^E.) Plate xxiii. 

382. hungancus, ij in. shell broader than long, yellowish white 

to light brown, beak overhanging the 
posterior side. 

Cardium. (CARDIIDJE.} Plate xi. 

Front margin contracted 

133. exignum, Jin. x Jin. yellowish white, marked with brown and 
pink. , 

131. tuberculatum,3%in, x 3in. yellowish brown, tinged with red. 



GENERA AND SPECIES. I 13 

Hinge line angular 

129. acnlcatum, 3^ in. x 3^ in. ribs large and spiny. 

138. norvegicum, 2 Jin. x 2 in. ribs faint and smooth, and absent on sides. 

Hinge line curved 

130. echinatum, 2 J in. x 2* in. ribs with triangular spines. 

136. edule, if in. x ij in. ribs with crested plates. 

134. fasciatum, J in. x J in. ribs prickly, but flat and smooth in front. 
132. papillosum,^ in. x J in. ribs with white tubercles. 

135. iiodosum, Jin. x Jin. ribs rounded at the sides and covered with 

tubercles or spiny plates. 

137. minimum, fin. x -gin. ribs flat and covered with arched scales, 

often in a double row. 

Of 130 there are two varieties expansa, which is wider, ami ovata, which has ribs 
much narrower than the furrow.s and a nearly straight dorsal margin. 

Of 132 there is a white variety lactea. 

Of 133 there is a variety subquadrata. which is squarish in shape. 

Two varieties of 134 have been named globosa,Vi\\\ch has the posterior side shorter, and 
alba, which is white. 

Two varieties of 135 have also been named ovata, which is wider and coarsely marked, 
and rosea, which is rosy pink. 

There are two varieties of 136 tustica, which is brown or orange in colour, and 
small and thin, with the posterior side more wedge-shaped ; and cremilata, which is more 
oval and has the front margin straight. 

Of 138 there are three varieties gibbet, which is smaller and more oblique; rotunda, 
which is Hatter and rounder ; and. pallida, which is pale yellow in colour. 



Carychium. (AURICULID^E.) Plate xviii. 
201. minimum, ^ in. shell transparent, whorls 5^. 

Ceratisolen. (SOLENIDJE.) Plate xiii. 

151. legumen, 4in.xiin. shell smaller at the anterior end, and pale 
yellowish white. 

Cerithiopsis. (CERITHIID&.) Plate xxiv. 

447. lubercularis, in. . colour brown, 2 basal ridges, 13 or 14 whorls, 

last whorl but one with three rows of 
tubercles. 

448. barleei, in - yellowish white, no basal ridges, 12 whorls, 

last whorl but one with three rows of 
tubercles. 

449. pulchella, J in. yellowish brown, 4 thin ridges on the body 

whorl, 10 whorls, closely whorled and 
cancellated. 

450. metaxa, % in. yellowish brown, 14 or 15 whorls, 5 thick 

ridges on the body whorl, and 4 on each of 
the other whorls. 

451. costulata,' |- in. white, 12 whorls, longitudinal ribs promi- 

nent, sharp and curved. 
There is a variety of 447 nass.i which is shorter and broader in proportion. 



GENERA AND SPECIES. 



Cerithium. (CERITHIIDJE.) Plate xxiv. 

443. metula, f- in. white, mouth oblong, 18 to 20 whorls. 

444. reticulatum, % in. white, mouth triangular, 1510 16 whorls. 

445. perversum, % in. brown, sinistral. 

446. vulgatum, ij in. shell grey and chocolate, with spiral nodulose 

ribs, a prominent row of nodules on each 
whorl. 

There are two varieties of 444 simplex, in which the ridges are marked with purplish 
lines ; and lactescens, which is whitish. 

There is also a variety of 445 pallescens which is whitish* 



Chiton. (CHITONID. 

190. fascicularis, 

191. discrepans, 

192. Jianleyi, 

193. cancellatus, 

104. cinereus, 

195. fl#WS, 



.) Plate xvi. 
fin 



girdle, broad, spinous, with whitish tufts, 
beaks small. 

in. girdle broad, spinous, with greyish tufts, 
beaks sharp and projecting. 

in. girdle narrow, spinous, without tufts, beaks 
small and'pointed. 

in. girdle narrow, covered with granules, beaks 
inconspicuous except on tail plate, colour 
yellowish white. 

in. girdle narrow, covered with granules, beaks 
small, colour pale yellow. 

in. girdle broad, beaded with granules, ridge 
sharp and conspicuous, colour yellowish 
white. 

196. marginatus, $ in. girdle covered with granules, ridge prominent, 

beaks strong and conspicuous. 

197. ruber, in. girdle broad, mealy, and covered with 

granules, ridge indistinct, beaks projecting, 
colour brown, streaked with yellow. 

198. l&vis, J in. girdle broad, reticulated, and covered with 

scales. 

199. marmorens, i in. girdle broad, membranous, and covered with 

scales. 

200. scabridus, J in. girdle narrow, colour brown, with radiating 

granules. 

Of 190 there are two varieties attenuata, which is longer and narrower, and gracilis^ 
which is also larger and has a membranous girdle. Of 194 there is a variety rissoi which 
is pale yellow in colour, and of 197 there is also one variety oblonga which is longer and 
more arched. There is but one variety of 198, it is smaller and more arched, and is known 
as navicula. 



Circe. (YEN BRIDGE.) 
113. minima, in. x 



Plate ix. 

in. shell with flat concentric ridges, and of 
many colours. 

There is a variety triangulates in which the beaks are more prominent, and the 
sides more acute. 



GENERA AND SPECIES. 115 

Clausilla. (PUPID^E.} Plate xx. 

Margin of clausilium notched 

304. biplicata, f in. 2 folds on pillar, shell streaked. 

305. laminata, f in. 3 or 4 folds on pillar, shell smooth. 

Margin of clausilium entire 

306. rolphii, J in. 4 or 5 folds on pillar, shell fusiform and 

streaked. 

307. rugosa, J in. 3 folds on pillar, shell streaked. 

308. parvula, in. 3 folds on pillar, shell smooth. 

309. solida, i in. shell very narrow, tooth more than half 

across mouth. 

Of 305 there are two varieties pellucida, which is more transparent, and albfda, which 
is greenish white. Among the varieties of 307 are alftida, which is greenish white ; 
everetti, which is small ; gracilia, which is long and slender ; tumidula, which is short and 
stout ; dubia^ which is large and stout ; and dextrorsa, which has a dextral spire. 

Clio. (CA VOLINIID&.) Plate xxx. 

584. pyr ami data, in. 5 ridges in front and one at the back. 

Clione. (CLIONID^.} Plate xxx. 

585. limacina, i in. no shell ; head distinct ; gills external. 

Cochlicopa. (PUPID^E.) Plate xx. 

310. lubrica, J in. mouth without teeth or folds, 

311. tridens, Jin. mouth with teeth and folds. 

There are five varieties of 310 hyalina, whicr s greenish white ; Inbricoides^ which is 
small arid slender; viridnla, which is also small and slender, and is greenish white \fusca, 
which is brown ; and ovata, which is oval and has a shorter spire. Of 311 there is only one 
variety crystalline which is greenish and transparent. 

Columbella. (COLUMBELLID^E.) Plate xxvi. 

511. haliaeti, Jin. whorls 8, outer lip furrowed inside, spire 

turreted. 

512. nassa, J in. whorls 5, outer lip smooth, spire tapering 

and not turreted. 

Corbula. (MYIDM.) Plate xii. 

146. gibba, % in. colour yellowish or brownish white. 

There is a variety rosea which has a purple streak on each side of the beaks. 

Crenella. (MYTILID&.) Plate ii. 

24. rhombea, Jin. x in. shell with from 12 to 15 transverse plates. 

25. decussata> J in. x^ in. shell with 40 to 50 transverse striae. 



Il6 GENERA AND SPECIES. 

Crepidula. (CAPULID^E.) Plate xxiii. 

384. fornicata, 2 in. x i in. smooth, pinkish white, with radiating 
irregular chestnut lines often broken up 
into spots. 

Crimora. (POLYCERIDJE.) Plate xxxiii. 

608. papillata, f in. a ridge of yellow papillae down each side of 

the back. 

Cyamium. (CARDITIDM.) Plate v. 

49. minutum, -fa in. x jV in. colour purplish brown, teeth tinged with 
purple. 



Cyclostoma. (CYCLOSTOMATIDJ5.) Plate xxiii. 

397. elegans, fin. pale brown, with a purple tinge, whorls 

umbilicus twisted. 



Cyclostrema. (CYCLOSTREMATIDM.) Plate xxi. 

335. cutler ianum, 5 in. shell globular, umbilicus exposing only base 

of last whorl. 
336 nitens, -fa in. shell sub-globose, umbilicus not exposing any 

part of the middle whorl. 

337. serpuloides, $ in. shell depressed, umbilicus exposing the 

whole of the spire. 

This genus was established by Captain Frederic Marryat, F.R.S., who did so much 
in many ways, though most people know him only by his novels. 



Cylichna. (SCAPH AN BRIDGE.} Plate xxx. 

560. acwninata, $ in. shell fusiform. 

561. nitidula, j n . shell oblong and tapering at the end, smooth 

and iridescent. 

562. wribilicaia, in. shell oblong, spirally striated, creamy and 

opaque. 

563. cylindracea, f in. shell cylindrical, outer lip straight in the 

middle. 

564. alba, J in. shell cylindrical, outer lip curved. 

There is one variety of 562 conulus which is longer and conical in shape ; and of 563 
there is a variety linearis which is shorter, with brown spiral lines at the ends. 

Cypraja. (CYPR&IDJE.) Plate xxv. 
457. europaa, J in. shell roundish and longitudinally ribbed. 

Cyprina. (CYPRINIDM.) Plate v. 

53. islandica, 4^ in. X4in. shell thick, colour brown. 



GENERA AND SPECIES. 117 

Dendronotus. (DENDRONOTIDJE.) Plate xxxii. 

599. arbonscens, i in. brown, spotted with white ; head-veil with 

four or more branched processes. 

There are two varieties of this lactea, which is white, and pulchella, which is pink. 

Dentalium. (DENTALIIDJE.) Plate xv. 

187. entalis, ij in. ivory white, no longitudinal striae towards 

narrower end, where there is often a slit. 

188. tarentinum, ij. in. creamy white, often pinkish at the point, 

longitudinal striae along lower half, plug 
at posterior end, where there is never a slit. 

189. abyssorum, if in. white, banded with pale blue, longitudinal 

streaks at lower half, plug at posterior end. 

Of 187 there is a variety annulata which has white rings of growth ; and there is also 
infuudibulum, which is shorter and more conical. 



Diplodonta. (LUCLNIDJE.) Plate vii. 



65. rotundata, lin.x^ 

Donax. (DONACID&.} 

104. vittatus, 

105. trunculits, 

1 06. folttus, 



white, periostracum yellowish, usually 
remaining only in front. 



Plate viii. 



posterior margin obliquely truncate, longitu- 
dinal striae crossed by transverse striae. 

posterior margin abruptly truncate.no trans- 
verse or concentric striae. 

smooth, inner edge not toothed. 



Doris. (DORWID&.) Plate xxxiii. 

Gills united at base, and retractile within a cavity 

repanda, i in. gills 5. 

millegrana, ij in. gills 6, dorsal tentacles conical. 

zetlandica, f in. gills 6, dorsal tentacles linear. 

testudinaria, 2 in. gills 8. 

flammea, i in. gills 9, body scarlet. 

tuberculata, 3 in. gills 9, body orange or yellow. 

603. coccinea, % in. gills 10. 

johnstoni, if in. gills 15. 

Gills simply pinnate, non-retractile ; no oral tentacles 
oblonga, J in. gills 7. 

pusilla, J in. gills 9, dorsal tentacles white. 

sparsa, J in. gills 9, dorsal tentacles white, blotched with 

brown, and with tubercles at base. 
inconspicua, % in. gills 10. 



Il8 GENERA AND SPECIES. 

aspen, J in. gills n, white, dorsal tentacles sub-conical. 

proxima, Jin. gills n, orange yellow. 

muricata, J in. yellowish white, mantle with large close set 

tubercles. 

loveni, J in. gills n, yellowish white, mantle with large 

distant tubercles. 

ulidiana, J in. gills n, pale yellow. 

diaphana, J in. gills n, white, dorsal tentacles linear. 

depressa, Jin. gills n, light brown, spotted with reddish 

brown. 
bilamcllata, ij in. gills 20 to 29. 

Gills united at base, non-retractile 

quadrangulata, i in. gills 7, dorsal tentacles in smooth sheaths. 

pilosa, i^ in. gills 7 to 9, dorsal tentacles in toothed 

sheaths. 

Doto. (DOTONIDJE.} Plate xxxii. 

fragilis, i in. foot notched in front. 

pinnatifida, f in. foot arched in front and rounded. 

598. coronata, Jin. tubercles of gill processes tipped with purple. 

cuspidala, J in. tubercles of gill processes without purple 

tips. 

Dreissensia. (DREISSENSIIDM.} Plate vii. 

60. polymorpha, i^ in. shell mussel-shaped, and keeled in the middle 

of both valves. 

Elysia. (ELYSIID&.) Plate xxxi. 
588. viridis, f in. body green, with bright blue metallic spots. 

There is a variety of this olivacea, which is brownish, with blue and red dots, and 
white tips to the tentacles. 

Emarginula. (FISSURELLID&.) Plate xxi. 
Beak overhanging 

330. rosea, % in. shell broader in front than behind. 

Beak not overhanging 

329. fissura-, J in. colour whitish, sides of slit parallel, ribs 25 

to 35- 

331. crassa, i in. white, slit wider below. 

332. cancellala, J in. white or yellowish slit a quarter as long as 

shell, shell ovate, anterior slope convex, 
posterior slope straight, 62 to 68 radiating 
ribs, alternately large and small. 



GENERA AND SPECIES. 



Embletonia. (^EOLIDID^E.) Plate xxxi. 

pulchra, 



592. minuta, 

pallida, 
gmyi, 



in. gill processes in single series, body flesh 
colour, spotted with white. 

in. gill processes in single series, body pinkish 
yellow. 

in. gill processes in double series, 
in. gill processes in triple series. 



Euliina. 

464. stenostoma, 
466. bilineata, 

465. subulata, 
463. distorta, 
462. intermedia, 
461. polita, 



E.) Plate xxv. 

^ in. whorls 9, colour white. 

in. whorls not exceeding n, white, encircled 
by a pair of thin brown bands. 

in. whorls not exceeding 13, white, encircled by 
three pairs of thin brown bands. 

in. whorls not exceeding 15, white, spire curved, 
quite smooth. 

in. whorls not exceeding 16, white, spire never 
curved, marked with faint spiral lines. 

in. whorls not exceeding 18, white, faintly can- 
cellated, whorls nearly flat, spire 
occasionally curved. 



Fiona. (JEOLIDIDjE.) Plate xxxii. 

593. nobilis. 2 in. buff, with a brown central gland. 

Fissurella. (FISSURELLIDM.) Plate xxi. 

326. graca, f in. yellowish white, with brownish rays. 

327. gibba, J in. pink, with greenish rays. 



Fusus. (FASClOLARLIDjE. 

Spirally striated, 
526. Jeffrey sianus, 2% in. 



Plates 



xxvn., xxvin., xxix. 



525. propinquus, 

521. norvegicus, 

520. antiquus, 

522. turtoni, 

523. islandicus, 

524. gracilis, 



3iin. 
4 f in. 

3 in. 



but not longitudinally ridged 

outer lip curved in the middle, canal very 
short. 

spire turreted. 
spire short. 

whorls 7 or 8, angulated on upper edge, 
canal angulated and short. 

whorls 7 or 8, whorls angulated on upper 
edge, canal curved and very short. 

whorls 9, apex a bulbous point, suture 
broad, canal long and straight. 

whorls 9, apex without bulb but twisted 
in front, suture narrow, canal short and 
curved. 



120 GENERA AND SPECIES. 

Spirally striated and longitudinally ridged 

527. berniciensis, 3^ in. pinkish white, inside of outer lip grooved, 

pillar slightly angulated. 

528. jenestratus, if in. yellowish white, inside of outer lip plain, 

pillar sharply angulated. 

Of 520 there are about a dozen monstrosities ; of the varieties the chief are alba, which 
is white and much larger ; ventricosa, which has the whorls larger ; striata, which is ridged 
on the upper whorls ; and gracilis, which is spirally ridged and more slender. Of gracilis 
(the <species, not the variety) No. 524, there is a variety convoluta which is smaller and 
has a longer spire and deeper suture. Of 525 there is also a variety with a longer spire and 
smaller, this is turrita, which was at one time known as Tritonium turritutn. 

Galeomma. (GALEOMM1D&.) Plate vii. 

80. turtoni, in. x ^ in. shell thin and compressed towards each 
end. 

Gastrana. (TELLINID&.) Plate viii. 
98. frag His. ij in. x i in. ligament annulated irregularly. 



Gastrochcena. (GASTROCHCENIDM.) Plate xiv. 

159. dubia. ^ in. xf in. shell obliquely twisted from the beaks. 

Geomalacus. (LIMACID&.) Plate xviii. 

246. maculosus, 2 in. black, spotted with yellow; foot brown, 

with a light yellow sole. 

Goniodoris. (GONIODORID^E.) Plate xxxiii. 
609. nodosa, i in. gills 13, pinkish or yellowish white. 

castanea, i in. gills 6 or 7, brown, spotted with white. 

Haliotis. (HALIOTIDsE.) Plate xxi. 

333. tuber culata. 4 in. brown and pale green, holes from 6 to S. 

Helcion. (PATELLIDSE.} Plate xxi. 

325. pellucidum, f in. brown, with thin streaks of blue. 

Helix. (HELICID^E.) Plates xix., xx. 

"Without umbilicus 

276. nemoralis, i in. lips brown. 

265. aspersa, if in. lips white, whorls 4^, spiral bands generally 

confluent, crossed by transverse patches. 

273. hortensis, i in. lips white, whorls 5 J, spiral bands distinct 

and not crossed by transverse patches. 



GENERA AND SPECIES. 121 

With umbilicus 
Over ^ in. across 
With labial rib- 
Shell bluntly keeled 

284. nifescens, J in. reddish brown, frequently with a white 

band on last whorl. 

Shell without a keel- 
Striped 

278. pisana, fin. shell with mottlings, umbilicus small and 

oblique. 

287. virgata, \ in. shell without mottlings, umbilicus narrow 

and deep. 

Unstriped 

266. cantiana, fin. shell tinged with rose, umbilicus narrow and 

deep. 

268. cartmiana, % in. shell horn colour, umbilicus minute. 

Without labis.1 rib- 
Shell globose 

279. pomatla, if in. shell large and striated, yellow, with broad 

bands of light brown. 

264. arbustomm, in. shell striated, brown, with blackish band 

along the middle of each whorl. 

Shell depressed, umbilicus large 

270. ericetovMK, f in. shell greyish with brown bands, mouth 

nearly circular. 

277. obvoluta, % in. shell rufous brown, mouth triangular and 

toothed. 

275. lapicida, in. shell rufous brown, mouth oval and 

angulated. 

Under J in. across 
Under in. across 

280. pukhdla, fa in. shell milky white. 

281. pygmcea, -fa in. shell pale horn colour. 

285. rupestris, in. shell blackish brown. 

Over in. across 
With labial rib 

267. caperata, % i n - shell keeled and striped with coloured 

bands. 

269. concinna, in. no keel and no stripes, umbilicus very large. 

272. hispida, % in. no keel and no stripes, umbilicus very 

small. 

286. sericea, J in. downy and granulated, greyish white, no 

keel and no stripes, umbilicus very small. 
I 



122 



GENERA AND SPECIES. 



272. hispida, 
286. sericea, 

283. rotundata 

271. fiisca, 

263. aculeala, 

274. lamcllata, 

282. revelata, 



Without labial rib 

in. no keel and no stripes, umbilicus small. 
in. 



no keel and no stripes, greyish white, 
transparent, umbilicus very small. 

in. bluntly keeled. 

in. wrinkled. 

in. raised periostracum, whorls 4 to 4^, mouth 

semicircular. 
in. raised periostracum, whorls 6, mouth cres- 

cent-shaped. 

in. greenish, hispid, transparent, umbilicus 
large. 

The species of Helix vary much in coloration, ; of many of them there are white 
varieties which it is not necessary to particularise. Of 265 there are varieties that are whitish 
or yellowish, and one that is reddish brown with a single white stripe, and there are two 
dwarf varieties. Of neinoralis and hortensis the varieties are too numerous to trouble about, 
a new one can be found in almost every parish ; arbustorumaXso varies very much in ground 
colour. Of 268 there is a variety rufilabris, which has a brown labial rib ; of 287 the most 
marked variety is subglobosa, which has a double band above the periphery, and of 267 there 
is subscalaris. which has a conical shell. 



Hermaea. (HERMJEID^.} Plate xxxi. 

bifida, i in. body linear. 

586. dendritica, in. body ovate. 

Hero. (.EOLIDIDsE.) Plate xxxi. 

596. formosa, i in. rosy, with three whito lines. 

Homalogyra, (HOMALOGYRIDJE.) Plate xxiii. 

385. atornus, ^ in. smooth or obscurely ridged. 

386. rota, ^ in. ribbed and keeled. 



Hydrobia. (HYDROBIIDM.) Plate xxiv. 
429. jenkinsii, J in. mouth circular. 



426. ulvce, 

427. similis, 

428. ventrosa, 



in. whorls 7 or 8, mouth oval, narrowly 
angulated. 

in. whorls 5 or 6, suture deep, shell oval and 
stout mouth oval. 

in. whorls 6 or 7, suture rather deep, shell long 
and narrow, mouth oval. 



lanthina. (IANTHINID.E.) Plate xxii. 
357. fragilis, i^ in. outer lip entire, broad pale streak around 



358. rotundata, 

359. cxigua, 



pillar. 

in. outer lip entire, no streak around pillar. 
in. outer lip indented. 



GENERA AND SPECIES. 123 

Idalia. (GONIODORID&.) Plate xxxiii. 
611. elegans, ij in. white, spotted with rose; gills 18. 

leachii, i in. white, centre of back with filaments ; 

gills ii. 

aspersa, J in. reddish or yellowish, spotted with orange and 

brown ; gills 10. 

inaqualis, f in. grey, speckled with yellow and brown ; mouth 

with 4 filaments in front ; gills 9. 

pulchella, f in. pale blue, centre of back without filaments ; 

gills IT. 

quadricornis f in. mottled brown and white mantle, with 2 

filaments in front ; gills 8 or 9. 

Isocardia. (CYPRINIDM.) Plate v. 

54. cor, 3|X3f in - she11 globose, yellowish white, periostracum 

brown, 

Jeffreysia. (JEFFREYSIID^.) Plate xxiv. 

435. diaphana, ^ in. whorls 4^. 

436. opalina, -$ in. whorls 3^, shell oval and semi-transparent. 
437- globularis, -$ in. whorls 3^, shell globular and transparent. 

Kellia. (ERYCINID&.) Plate vii. 

73. suborbicularis, \ in. x \ in. right valve with two lateral teeth. 

74. cycladia, ^in. x-^in right valve with two lateral teeth and a 

cardinal. 

Lachesis. (MURICIDsE.) Plate xxvi. 

510. minima, in. shell ridged and cross-ribbed, apex twisted 

on one side. 

Lacuna. (LITTORINIDM.) Plate xxiii. 

Suture excavated 

394. tenella, in. whorls 5. 

392. crassior in. whorls 6 or 7. 

Suture not excavated 

395. puteolus, in. whorls 3 or 4, umbilicus narrow. 

396. pallidula, % in. whorls 3 or 4, umbilicus very wide. 

393. divaricata, J in. whorls 6. 

Of the three varieties of 393, quadrifasciata. is keeled ; 395 has five varieties of no im- 
portance ; and 396 has three named varieties, of which the most noticeable is patula, 
which has a flat spire. , 

Lamellaria. (LAMELLARIID&.} Plate xxiii. 

377. perspicua, $ in. shell ear-shaped, first whorl twisted. 



124 GENERA AND SPECIES. 

Lassea. (ERYCINID^.) Plate vii. 

75. rubra, J in. x^ in. white, tinged with red. 

There is a variety of this pallida which is tinged with yellow instead of red. 

Leda. (NUCULID&.) Plate i. 

5. pygmeea, ^ in. x^in. teeth like those of a comb, shell smooth 

and swollen. 

6. lucida, | in. xfy in. teeth like those of a comb, shell ribbed and 

thin. 

7. minuta, in. x J in. teeth like a herring bone, shell with about 

30 transverse ribs, posterior slope with 2 
ridges. 

8. permila, Jin.xf in. teeth like a herring bone, posterior slope, 

slight and having 3 ridges. 

Lepeta. (LEPETID^E.) Plate xxi. 

322. caeca, J in. white outside and inside, central scar dis- 

tinct. 

Lepton. (ERYCINIDM.} Plate vii. 

76. squamosum, J in. x f in. shell pitted, scars indistinct. 

77. nitidum, ^ in.Xj^in. shell pitted, scars distinct. 

78. sulcatulum.^m.x^in. shell grooved, hinge plate broad, faintly 

excavated. 

79. darkies, ^ in. x^ in. shell grooved, hinge plate narrow, deeply 

excavated 

Lima. (LIMIDM.) Plate v. 

46. subauriculata, ^ in. x^ in. shell equilateral, with 24 ribs. 

44. sarsii, ^in. xjin. shell equilateral, with 25 to 30 ribs, beaks 

small. 

45. elliptica, ^ in. x^in. shell equilateral, with 30 to 40 ribs, beaks 

prominent. 

47. loscombii, ^ in. xf in. shell inequilateral and oblique, with 50 to 

60 ribs, hinge nearly straight. 

48. hians, i in. x ij in. shell inequilateral and oblique, with 50 to 

60 ribs, hinge line much curved. 

Limapontia. (LIMAPONTIIDM.) Plate xxxi. 
589. nigra, ^ in. head truncated in front. 

depressa, f in. head rounded in front. 

Limax. (LIMACIDJS.) Plate xviii. 

234. flavus, animal 4 in. thick, rather square, yellowish, spotted with 
blackish-brown ; head and tentacles grey ; 
shell in. long by J in. broad; shield 

4 marked with granules. 



GENERA AND SPECIES. 



235. agrestis, animal ij in. 



236. lavis, 



237. tenellus, 



shield marked with concentric lines ; shell 
small and oblique ; keel on back set 
obliquely. 

animal dark brown, tinged with violet ; shell 
square and minute, breathing hole near 
centre of mantle's right margin. 

yellow mantle, body greenish white, head and 
tentacles black, shell oval, shield wrinkled, 
mucus yellow. 

greyish, spotted with yellowish white, 
central darker stripe, and a darker band on 
each side ; shell nearly flat. 

grey, spotted and striped with black, 
tentacles long and purple ; shell oblong ; 
^ in. by - in. 

breathing hole marked with darker tint than 
body ; sole with white band in the middle. 

Among the varieties of 234 are grisea and suffusa, both of which are grey, the former 
having brown and white tessellations. 

Of 235 there are nearly a dozen varieties, nigra being jet black, Jilans being greyish- 
white, punctata and nigricans being spotted with black, lilacina. being spotless, the usual 
albida, and subtnaculata. which is streaked and spotted. 

Of 236 there is but one variety maculata which is spotted dark brown. 

Of 238 there are three varieties bettonii, which has white and ruddy spots ; dicipiens, 
which has pale spots on a dark grey ground ; and maculata, which is spotted with black, 
and has a thin band on each side. 

There are some nine varieties of 239, among them being cinerea, which is ashy with a 



238. arborum, 



239. maxtmus, 



240. ctnereo-mger, 



3 in. 



6 in. 



4 in. 



black mantle ; ferrussaci, which is white, with four rows of black spots ; cellaria, which is 
ashy with black spots and bands ; fasciata, which is ashy white with five whitish bands ; 
obscura, which is brown ; rufescens, which is ruddy ; and marmorata, which is marbled 
with brown. Of cinereo-niger there is a black variety nigra. 



Llmnsea. (LtMtfMIDM.) Plate xvii. 

207. auricular ia, i J in. whorls 4 or 5, last whorl enlarged ; spire 

short and acute, inner lip forming small 
umbilical fissure behind it. 

208. glabra, in. whorls 7 or 8, spire long, mouth with 

broad internal white rib. 

209. glutinosa, J in. spire very short but not sunken ; whorls 3 

or 4, last whorl forming nearly the whole 
of the shell ; suture shallow, mouth oval 

210. involute, in. spire very short and sunken, suture deep, 

mouth pyriform. 

211. palustris, i in. whorls 6 or 7, less rapidly enlarging than 

213 ; spire long, suture deep. 

212. feregra, f in. whorls 5, last whorl enlarged, inner lip 

folded on pillar and forming narrow groove. 

213. stagnalis, 2 in. whorls 7 or 8, last whorl enlarged, suture 

deep. 

214. truncatula, f in. whorls 5 or 6, spire long, suture very 

deep, umbilical fissure distinct. 

There are over sixty varieties of the species of Limnaa, most of them differing from the 
type in having a larger or smaller lip and a longer or shorter spire ; some are decollated, 
some sinistral, some white, but as a rule the differences are so slight that it has hitherto been 
impossible to describe them satisfactorily. 



125 GENERA AND SPECIES. 

Limopsis. (ARCADE.) Plate i. 

17. aurita, in. x^ in. ridges of shell beaded. 

18. borealis, J in. x^ in. ridges of shell not beaded. 

Littorina. (LITTORINIDJE.} Plate xxiii. 

387. obtusata, in. shell over inch long, spire depressed, 

colours various. 

388. neritoides, in. shell about Jinch long, spire pointed, colour 

brown. 

389. mdis, in. shell inch, spire pointed, suture distinct. 

390. littorea, i^ in. shell over f inch, spire pointed, suture in- 

distinct. 

391. astuarii, f in. shell under inch, spire slightly raised and 

compact, colour greenish brown. 

Lomanotus. (LOMANOTID&.) Plate xxxii. 

597. mannoratus, % in. body drab marbled with brown and white. 

flavidus, J in. body pale yellow above, white below. 

portlandicus, if in. body white, light brown on back, and bright 
red in front. 

Loripes. (LUCINID^.) Plate vii. 

63. lacteus, % in. x 5 in. margin smooth and plain. 

64. divaricata, fin. x in. margin finely toothed. 

Lucina. (LUCINID&.) Plate vii. 

61. spinifer, I in. x ^ in. hinge line an obtuse angle, inside pearly. 

62. borealis, i in. x if in. hinge line curved, inside white. 

Lucinopsis. (VENERIDM.) Plate x. 

122. undata, i in. shell circular, white, yellowish at the beaks. 

A variety, cequalis, has a squarish shell, with more prominent beaks. 

Lutraria. (MYIDJE.) Plate xii. 

147. elliptica, 5^ in. x 3 in. shell elliptical. 

148. oblonga, 4 in. x 2 in. shell turned up at posterior end. 

Lyonaia. (LYONSIID&.) Plate xv. 

173. norvegica, i|in. x ^in. shell rhomboidal, cartilage golden yellow, 
ossicle quadrangular. 

Mactra. (MACTRIDJS.) Plate ix. 

108. solida, if in. x if in. white, beaks projecting slightly. 

109. elliptica, ij in. x f in. shell elliptical and thin, beaks not projecting. 



GENERA AND SPECIES. 



127 



no. siib-truncata,i^ in. xf in. white, angulated on both sides, striated 
round the beaks, which project boldly. 

in. stultorum, 2 in. x ij in. yellowish brown, rayed with white. 

Ti2. glauca, 4 in. x 3 in. yellowish brown and white, without rays. 

Mangilia. (CONID^E.) Plate xxix. 
Spire not turreted 

530. teres, f in. yellowish white with brownish spots, spire 

long, whorls 10. 

531. gracilis, i in. pale purple, canal long. 

532. lenfroyi, f in. cream with brownish blotches, spire short, 

canal short, whorls 8 or 9. 

533. linearis, in. white with brown lines, spire long, canal 

short, whorls 8 or 9. 
Spire turreted 

534. reticulata, J in. yellow mottled with brown, whorls 9 or 10, 

outer lip with less than 12 ridges, 
canal long. 

535- puypurea, i in. brown, often mottled with a lighter colour, 

outer lip with more than 13 ridges, canal 
short. 

There is a variety of 532, carnosula, which is rather larger and flesh colour ; of 533 there 
is also a larger variety, cequalis, which is broader and has more ribs ; of 534 there is a white 
variety, fonnosa ; and of 535 there are two varieties which are smaller, one of which, 
obtonga t has the spire not turreted. 

Marginella. (MARGINELLID^E.) Plate xxix. 
529. Icevis, | in. outer lip with many notches or teeth. 

Melampus. (AURICULIDM.) Plate xvii. 

202. bidentatus, \ in. ivory white. 

203. myosotis, $ in. rufous brown or yellow, purple towards tip 

Modiolaria. (MYTILID^.) Plate ii. 

26. marmorata, in. x fin. hinge toothless, shell oval. 

27. costulata, ^ in. x in. hinge toothless, shell oblong. 

28. discors, ^ in. x in. hinge toothed, hinge plate toothed. 

29. nigra, in. x ij in. hinge toothed, hinge plate finely notched. 



Montacuta. (LUCINID&.) 

69. substriata, J in. x in. 

70. bidentata, ^ in. x J in. 



Plate vii. 

yellowish white, hinge line slightly curved. 

milk white, hinge line nearly rectangular, 
scars obscure. 

yellowish brown, hinge line rectangular, 
beaks prominent, scars distinct. 

72. ferruginosa, in. x in. greyish white, hinge line almost straight, 
beaks not prominent, scars distinct. 



71. 



tumidula, 



128 GENERA AND SPECIES. 

Murex. (MURICID&.) Plate xxvi. 

506. erinaceus, 2^ in. colour yellowish white, spire turreted. 

507. aciculatus, in. colour reddish brown, spire not turreted. 

Mya. (MYID/E). Plate xii. 

143. arenaria, 4 in. x 2^ in. gaping equally at both ends. 

144. truncata, 2 in. x 2 in. gaping more at posterior end, inside chalky 

white. 

145. binghami, ^ in. x ^ in. gaping at posterior end, inside porcellaneous. 

Mytilus. (MYTILIDJE.) Plate ii. 

19. edulis, i in. x 2^ in. hinge with from 3 to 10 teeth, beaks 

divergent. 

20. modlolus, 2% in. x 5 in. hinge toothless, shell oblong, beaks 

divergent. 

21. barbatus, tin. x i in. hinge toothless, shell triangular, beaks in- 

curved andtlose to point, margins thick. 

22. adriaticus t $in. x i-Jin. hinge toothless, shell oval, beaks incurved 

and remote from point, margins thin. 

23. phaseolinus,^in. x in. hinge finely toothed, beaks incurved. 

There are four varieties of 19, the most marked of which is pellucida, 'which is striped 
with brown and purple ; of 20 there are two varieties ; of 21 there is a variety which has the 
upper valve flat and much smaller than the other ; the only variety of 22 is ovalis, which 
has an almost cylindrical shell quite two inches long. 

Nassa. (NASSID^.) Plate xxvi. 

514. nitida, i in. spire turreted, whorls flat. 

Spire not turreted 

513. retictilato, ij in. whorls convex or flattened, mouth white, 

outer lip with teeth inside. 

515. incrassata, f in. whorls angulated, mouth white or pinkish. 

516. pygmaa, / 5 in. whorls rounded, mouth brown. 

Natica. (NATICIDJE.) Plate xxiii. 

370. islandica, i in. spire produced. 

371. grcenlandica, in. whorls 4 or 5, spire short, umbilicus small. 

372. sordida, ij in. whorls 5 or 6, umbilicus large, spire short, 

mouth equal in length to two-thirds of 
spire, inner lip brown. 

373. catena, i in. whorls 7, and rounded, spire short, 

umbilicus large. 

374. alderi, f in. whorls 6, spire short, umbilicus small. 

375. montacuti, J in. whorls 5 or 6, spire short, umbilicus large, 

inner lip white. 

376. affinis, % in. spire short, umbilicus covered by a pad. 



GENERA AND SPECIES. I2Q 

Nezera. (POROMYID^E.) Plate xv. 

180. abbrcviata, in. x in, hinge line obtusely angular, shell nearly 

transparent. 

181. costellata, gin. x ^ in. hinge line straight, hinge plate narrow and 

slight, left valve with a small cardinal tooth. 

182. rostrata, ^ in. x /^ in. hinge line straight, hinge plate moderately 

broad, no cardinal tooth. 

183. cuspidata, in. x T ? in. hinge line obtusely angular, shell opaque 

and noticeably inequivalve. 



Neritina. (NERITID&.} Plate xxii. 

356. fluviatilis, i Q - whorls 3, the last exceeding two-thirds of 

the shell. 



Nucula. (NUCULID^E.) Plate i. 

Inner margin notched 

1. sulcata, f in. x in. beaks not terminal, teeth 10 to 12 on 

anterior side, and 20 to 24 on posterior side. 

2. nucleus, ^ in. x in. beaks terminal, teeth 15 on anterior side, 

and 25 on posterior side. 

3. nitida, ^ in. x J in. Shell shining, teeth 12 on anterior side, 

and 20 on posterior side, beaks prominent. 

Inner margin not notched 

4. tennis, % in. x ^ in. beaks thin, teeth 6 on anterior side, and 

1 6 on posterior side. 

Of 2 there is a variety, radiata, which is larger, flatter, and has radiating streaks 
of purple. 

Odostomia. (PYRAMIDELLIDM.} Plate xxvi. 

Pillar straight, shell smooth 

502. nitidissima, ^ in. whorls 7, suture wide and deep. 

501. acicula, in. whorls 8 or 9, not angulated, suture narrow. 

500. scilla, in. whorls n to 12, angulated, suture narrow. 

Pillar straight- 
Shell ribbed or reticulated 
Whorls more than 10 

497. vufa, in. whorls 10 to 13, colour drab, often blended 

with brown. 

498. lactea, % in. whorls 12, colour white, ribs curved and 

oblique. 

499. pusilla, in. whorls 12, colour white, ribs curved, but 

not oblique. 



130 



GENERA AND SPECIES. 



Whorls less than 10 
Spire turreted 

495- excavata, \ in. whorls 6, white, prominent spiral ridges and 

raised longitudinal ribs, outer lip with four 
angular points, pillar with tooth. 

496. scalaris, in. whorls 8, light yellow, ribs more prominent 

than striae, pillar without tooth. 

494. fenestratj, fy in. whorls 8 to 9, white, body whorl with 20 

longitudinal ribs crossed by 3 spiral ridges, 
pillar without tooth. 

Spire not turreted 
Pillar without tooth 

489. clathrata, % in. whorls 6 or 7, 3 rows of ribs on body whorl. 

490. indistincta, ^ in. whorls 7 or 8, 6 to 8 rows of ribs on body 

whorl. 



Pillar with tooth 

493. eximia, ^- r in. mouth oval, whorls 4 or 5, ribs on body 

whorl 15, crossed by 3. 

492. spirahs, J in. mouth oblong, whorls 5 or 6, ribbed length- 

ways above and spirally beneath. 

491. interstincta, ^ in. mouth oval, whorls 5 or 6, over 18 ribs on 



body whorl. 



Pillar curved 
Shell turreted 



488. decussata, 



in. whorls 4, ribbed and spirally striated. 



470 truncatula, 



Whorls 5 or more 
Whorls flat 



whorls 6 or 7, no prominent ridge bordering 
suture, suture channelled. 



Whorls convex 



485. oUiqua, 

486. warreni, 

481. tiirrita, 
483. insculpta, 

482. plicata, 



whorls 5, swollen, basal striae faint, umbili- 
cus none or indistinct, mouth pear-shaped. 

whorls 5, swollen, basal striae distinct, 
umbilicus small but well marked, mouth 
pear-shaped. 

whorls 5 or 6, mouth square. 

whorls 6, convex, spirally striated, suture 
narrow, mouth irregularly oblong. 

whorls 5 or 6, shell thin and slender, spire 
long and finely tapering, mouth oval and 
angulated above. 



GENERA AND SPECIES. 13! 

477. umbilicaris, ^ in. whorls 5 or 6, shell a short cone ; spire 

short, apex inverted, mouth oval, expanding 
below. 

474. rissoides, in. whorls 5, quickly enlarging, spire tapering 

to a blunt point, mouth oval. 



Shell not 

487. dolioformis, % 

476. conoidea, % 

479. conspicua, % 



turreted 
in. whorls 3, body whorl very round. 

in. whorls 8, colour ivory-white, mouth oval, 
outer lip with 8 or 9 grooves. 

i n whorls 8, colour chocolate or cream, mouth 
squarish, angulated below, outer lip not 
grooved. 



484. diaphana, 

469. nivosa 
468. minima, 

471. clavula, 
473. albclla, 

472. lukisi, 

480. unidentata 
478. acuta, 

475. pallida, 



Whorls 4 to 7 



^ in. whorls 4, convex, upper part of each having 
a thickened rim. 

^ in. whorls 4 or 5, tooth large, with umbilicus. 

$ in. whorls 4 or 5, mouth oval. 

^2 in. whorls 4 or 5, mouth oval, expanded below. 

in. whorls 5 or 6, nucleus apparent on apex of 
spire, tooth small, without umbilicus. 

^,- in. whorls 5 or 6, mouth oval, expanded below 
and contracted above, spire abrupt. 

^ in. whorls 6, flat, no umbilicus. 

in. whorls 6, mouth oval, expanded below and 
contracted above, spire long and tapering. 

in. whorls 6 or 7, nucleus not apparent at apex 
of spire, tooth small, with umbilicus. 

Of some of the species of OJostotnia there are several varieties, but none worth special 
mention. 

Onchidium. (ONCHIDIID&.} Plate xx. 
318. celticum, in. tentacles short and conical, with bulbous tips. 

Ostrea. (OSTREID&.) Plate iii. 
32. edulis, 3j in. x 3 in. beaks small, lateral edges toothed or notched. 



Otina. (OTINIDM.) Plate xvii 
204. otis, 



in. shell earshaped, thin and transparent, 
whorls 2. 



Ovula. (CYPRJZIDJE.) Plate xxv. 

458. patula, i in. upper canal semi-tubular, lower canal short 

and broad. 



Pandora. (PANDORIDM.} Plate xv. 
172. inaquivalvis, i^in. x fin. right valve overlapping left. 



132 GENERA AND SPECIES. 

Panopaea. (GLYCIMERID&.) Plate xiv. 
158. plicata, in. x J in. shell with a long gape at the posterior end. 

Patella. (PATELLIDJE.) Plate xxi. 
324. vulgata, i in. shell a raised cone with radiating ribs. 

Of the five varieties of 324, picta is streaked with red and dark blue, intermedia has an 
orange crown, depressa is rather flat and has the beak near to the anterior end, and carulea 
is dark blue inside. 

Pecten. (PECTINID&.) Plate iii. 

33. pusio, if x if in. right hand ear of lower valve notched at 

base, 50 or more narrow ribs, alternately 
large and small. 

34. varius, i x if in. right hand ear of lower valve notched at 

base, 25 to 30 equal sized prickly ribs. 

35. opercularis, 2% x 2^ in. ears nearly equal, 20 rounded ribs. 

36. septemradiatus, ij x i^ in. right i^and ear the larger, 7 rounded 

ribs, middle one the largest. 

37. tigrinus, f in. x 3^ in. striated, purple streaked and blotched, 

right hand ear of lower valve the larger. 

38. testa, % in. x ^ in. apparently smooth, but really striated, left 

ear of upper valve deeply notched. 

39. striatus, f in. x f in. finely ribbed, left ear of upper valve nearly 

entire. 

40. similis, ^ in. x J in. striated and mottled, ears long and drooping 

and rounded at the corner. 

41. aratus, fin. x fin. ears large, 32 rounded ribs with thin plates 

in interstices, inside furrowed. 

42. vitreus, ^ in. x f in. striated, ears broadly triangular, except the 

right one of lower valve, which is irregular. 

43. maximus, 5 in. x 4^in. upper valve nearly flat, and concave towards 

the beak. 

There is a white variety of 34, nivez ; and there is a white variety of 35, lineata ; the 
latter having a thin brown line down the ridge of each rib ; of 36 there is also a white 
variety. No. 43 is not the scallop shell of the pilgrims, that species has the ribs of the lower 
valve angulated instead of round. The other varieties are of no importance. 

Pectunculus. (ARCADsE.) Plate i. 

16. glycimeris,2%in. x 2|in. shell round and white, zigzagged with browns 
and purples. 

Petricola. (PET RICO LI D/E.} Plate x. 
128. pholadiformis, ij in. x f in. thin, tumid, anterior side short. 

Phasianella. (TURBINIDM.) Plate xxii. 

355. pulla, ^ in. x in. many coloured, pointed at both ends, spire 
short, operculum white. 



GENERA AND SPECIES. 



133 



Philine. (PHILINIDJE.) Plate xxx. 

Patterned with dots or links 

569. scabra, fa in. whorls 3, outer lip indented in the upper 

part, mouth angulated. 

570. catena, $ in. whorls 2 or 3, outer lip indented in the 

middle, mouth oval. 

571. angulala, ^ in. whorls 2 or 3, conspicuous and keeled, 

mouth square. 

572. quadrata, \ in. whorls 2 or 3, rounded, mouth oval, top of 

outer lip scalloped, top of outer lip higher 
than spire, 

573. punctata, ^ in. whorls 2, rounded, mouth oval, top of outer 

lip scalloped and lower than spire. 

Cancellated 

574. pruinosa, J in. spire small, sunk below the crown. 

575. nitida, ^ in. spire smooth and conspicuous. 

576. aperta, in. spire loosely coiled and inconspicuous. 



Pholadidea. (PHOLADID&.} Plate xiv. 

164. papyracea, ijin. x fin. two dorsal shields, small and close to the 
hinge on anterior side ; shell with transverse 
ridges on the upper half, and smooth below. 



Pholas. (PHOLADID&.} 
1 60. dactylus, 5 in. x ij in. 
161. Candida, 2| in. x 



162. parva, if in. x 

163. crispata, 2j* in. x i 



Plate xiv. 

four dorsal shields. 
i in. one dorsal shield, 



which is broadly 
lanceolate, ribs radiating from beak. 

in. one dorsal shield, which is curved and 
narrowly lanceolate, ribs transverse. 

in. one dorsal shield, which is small and tri- 
angular, ribs longitudinal. 



Physa. (PHYSIDM.) Plate xvii. 

227. acuta, f in. whorls 3 to 5, mouth ending in a sharp angle. 

228. fontinalis, J in. whorls 4 to 5, spire short. 
224. hypnorum, f in. whorls 6 to 7, spire long. 



Pinna. (AVICULIDJE.) 
31. rudis, 15 in 



Plate iii. 

fan-shaped, surface minutely punctured 
hinge plate folded over the ligament. 



Pisidium. (CYRJENID&.} 
85. antnicum, f x J in. 



86. fontinalis, 



Plate vii. 



shell triangular, inequilateral, with the 
anterior side the longer. 

in. shell triangular, striated concentrically, 
posterior side much produced and rounded* 



GENERA AND SPECIES. 

^ x ^ in. shell round, anterior side truncate and 

rounded, posterior side produced and 

sloping abruptly. 
X in. shell oval, both sides rounded and 

compressed, 
f- X ^jy in. shell oblong, anterior side truncate and 

sloping abruptly below, posterior side 

produced and rounded. 

There are varieties of all the species olPisidittm except roseitw, the most marked being 
henslowana of 86, which hai a plate-like appendage to the beaks. 

Planorbis. (LIMN&ID&.) Plate xvii. 

Last whorl embracing the rest 



134 

87. nitidum, 

88. pusillum, 

89. roseum, 



222. lineatus, 
224. nitidus, 



in. whorls 4, septa in last whorl. 

in. whorls 4 or 5, thin, shining, compressed, 
keeled in middle. 



Last whorl not embracing the rest 
Whorls rounded 



215. albus, 

218. contortus, 

219. corneus, 

221. glaber, 

216. carinatus, 

217. complanatus, 

220. dilatatus, 
223. nautikus, 

225. spirorbis, 

226. vortex, 



^ in. whorls 5, shell small, greyish white, covered 
with longitudinal strise ; last whorl large. 

^ in. shell small, thick, whorls 8, compact, mouth 
semilunar ; umbilicus large and deep. 

i in. whorls 5 or 6, rounded above and below, 
suture deep, mouth narrow and crescent 
shaped ; umbilicus large and deep. 

\ in. whorls 5, last whorl large ; shell convex 
above, concave below ; smooth, no circular 
striae ; umbilicus large. 

Whorls keeled or angulated 

J in. whorls 5 or 6, keel in middle of whorls, last 
whorl large, mouth obliquely oval. 

| in. whorls 5 or 6, keel on lower side of whorls, 
last whorl large, mouth rhombic. 

^ in. whorls 2, angulated, mouth very large and 
squarish, umbilicus small and deep. 

jLj in. whorls 3, last whorl rather large, small 
imbricated ridge, mouth oval, umbilicus 
large. 

in. whorls 5 or 6, one side concave the other 
flat, keel frequently blunt, mouth roundish, 
often ribbed with white, umbilicus wide and 
shallow. 



g in. whorls 6 to 8, upper side concave, under- 
side flat, keel on the lower margin and 
always well marked, mouth rhombic, 
umbilicus large and shallow. 

Among the noticeable varieties of Planorbis, zrecristata of 223, in which the periphery is 
deeply notched; compressed of 221, which is only depressed in the centre on the upper side; 
and coinpressa of 226, which has the keel nearly in the middle of the periphery. Nearly 
every species has a white variety. 



GENERA AND SPECIES. 



135 



Pleurobranchus. (PLEUROBRANCHID^E.) Plate xxx. 

580. membranaceus, 2 in. shell ear-shaped, membranous, outer margin 

dilated. 

581. plumula, . f in. shell oblong, corneous, outer margin 

straight. 

Pleurophyllidia. (PLEUROPHYLLIDIID&.) Plate xxxii. 

Go i. loveni, i in. brown, with thin white stripes and black 

specks, gills and tentacles yellowish. 



Pleurotoma. (CONIDJE.) Plate xxix. 

Whorls rounded 

549. trevelyana, % in. white, spire turreted. 

543. lavigata, 



in. yellow, with chocolate margins, spire not 
turreted. 



Whorls angulated 
Spire turreted 

539- xugulosa, J in. yellowish, with or without brown bands, 

whorls 7, canal truncated, outer lip with- 
out ledge. 

541. galenta, in. grey, conical and rather stout, whorls 7. 

547. rufa, ^ in. purplish brown, whorls 7. 

548. ttirricula, J in. white, whorls 7 or 8. 

540. brachystoma, -$ in. yellowish white or reddish brown, whorls 8 
or g, labial notch on the ledge at the top of 
the body whorl. 

536. stnolata, f in. buff, with or without brown bands, 

whorls 9. 

542. nebula, in. chocolate, whorls 10 or n. 



Spire not turreted 

537. attenuata, $ in. 

538. costata, in. 
544. nivalis, J in. 

Jin. 



545. carinata, 

546. septangularis, 



dark yellow with brown lines, whorls 9 
or 10, canal straight. 

yellow and brown, whorls 9 or 10, canal 
curved. 

white, whorls 10, labial notch below the 
junction of the outer lip with the periphery. 

white, whorls 9, keeled, labial notch half 
way along the space above the keel. 

reddish brown, whorls 8 or g, coarsely 
ribbed. 



There are several varieties, none sufficiently distinctive except perhaps cranchii of 547, 
which has twisted ribs. 



136 GENERA AND SPECIES. 

Polycera. (POLYCERIDM.) Plate xxxiii. 

604. quadrilineata, f in. white, occasionally spotted with black. 
ocellata, J in. black, spotted with white. 

lessoni, J in. green or yellow, with yellow tubercles. 

Poromya. (POROMYIDJE.) Plate xv. 
179. granulata, J in. x J in. inside pearly and lineated, scars triangular 

Proctonotus. (sEOLIDID^E.) Plate xxxi. 

594. mucroniferus, J in. gill processes ovate and mucronated, and 

white with yellow gland in centre. 

Propilidium. (LEPETID^E.) Plate xxi. 

323. ancyloides, -fa in. oval with compressed sides, thin laminar 

partition in interior, opening towards the 
anterior half. 

Psammobia. (PSAMMOBIID&.} Plate xii. 

136. tellinella, i in. x f in. yellowish white with violet and pink, finely 
striated behind. 

140. costulata, f in. x in. yellowish white with purple, strongly ribbed 

behind. 

141. ferroensis, iin. x i in. pink with yellow and white. 

142. vespertina, 2% in. x i|in. yellowish white with brown and lilac. 

PunctureUa. (FISSURELLID^.) Plate xxi. 

328. noachina, J in. beak twisted to the left, slit lanceolate, 

covered internally by a sheath. 

Pupa. (PUPIDM.) Plate xx. 

288. marginata, f in. mouth with i tooth, a white rib behind 

the outer lip, suture deep. 

291. umbilicata, g in. mouth with i tooth, suture shallow and 

oblique. 

289. ringens, $ in. mouth with 5 folds. 

290. secale, % in. mouth with 8 or 9 teeth, 2 or 3 on the 

pillar, 2 on the pillar lip and 4 inside the 
outer lip. 

Purpura. (MURICID&.) Plate xxvi. 

508. lapillus, i^ in. whorls 6 or 7, mouth oval, canal deep, with 

a corresponding notch outside. 

509. hamastoma, i in. orange coloured mouth and 2 rows of 

tubercles. 



GENERA AND SPECIES. 



137 



Rissoa. (RISSOIDJE.) Plate xxiv. 
Outer lip plain- 
Shell smooth 

white, -with 4 rows of brown spots on 
body whorl ; whorls 4. 

cream, with 2 brown bands on body whorl, 
whorls 4. 

pale yellow, whorls 5, finely striated. 
white, whorls 6, finely striated and lustrous. 
white, smooth and dull ; whorls 6. 
white, with a row of brown streaks, whorls 6. 

white, with 2 brown bands on body whorl, 
whorls 6 or 7. 

Outer lip thickened and reflected 
Shell ribbed lengthways 

409. zetlandica, 

410. costata, 



420. piilchcri'ima, 


&in. 


421. fulgida, 


Jin. 


422. soluta, 


A*t 


418. proximo, 


f in. 


419. vitrea, 


fin. 


423. semistriala, 


A in- 


424. cingillus, 


iin. 



in. outer lip toothed, 16 ribs on body whorl. 
in. outer lip sinuated, 9 ribs on body whorl. 



Outer lip ribbed 
Shell cancellated 



407. punctura, 



405. cimicoides, 
400. striatula, 
406. jeffreysi, 


fin. 
iin. 
TIT in - 


402. cancellata, 


4 in. 


403. calathus, 


}in. 



punctured and prickly at angles of inter- 
section, colour white, often spotted with 
brown. 

outer lip toothed, whorls angulated. 

shell turreted, spire pointed, suture shallow. 

shell turreted, spire blunt and slightly 
truncated, suture deep and channelled. 

cancellations coarse, 16 ribs on body whorl, 
suture broadly excavated. 

cancellations minute, longitudinal striae as 
prominent as transverse striae; shell conical, 
spire acute. 

longitudinal striae faintly marked, shell 
oblong, spire acute. 

sne H oval . s P ire abruptly pointed, suture 
narrow and distinct, 20 ribs on body whorl. 

shell oval, spire short and abrupt, suture 
deep and channelled, whorls 5. 

Outer lip ribbed- 

Shell ribbed and spirally striated 

416. costulata, ^ in. striae punctured, suture deep, whorls 8, 

colour buff, with brown and lilac. 

413. albeila, f in. spire with a sharp point, suture very deep. 

417. striata, in. spire with a blunt point, suture deep. 
415. violacea, in. spiral striae punctured, suture narrow. 

K 



404. 



401. 



reticulate, 

lactea, 



408. abyssicola, 



\ in. 



in 



138 GENERA AND SPECIES. 

411. parva, % in. spire short, point blunt, spiral striae not 

punctured, suture narrow, no umbilicus. 

412. inconspicua, fa in. spire short and acute, spiral strias not 

punctured, tip of the spire pink, suture 
shallow, umbilicus small. 

414. membranacea, J in. spiral striae not punctured, tip of spire not 

pink, suture narrow, umbilicus small or 
absent. 



Runcina. (RUNCINIDM.} 
582. hancocki, ^ in 



Plate xxx. 

colour black, with buff ends; eyes large, 
surrounded by a pale ring. 



Saxicava. (GLYCIMERIDM.) Plate xiv. 

156. norvegica, 3 in. x 2 in. shell oval, hinge line straight. 

157. rugosa, if in. x f in. shell oblong, hinge line curved. 

Scalaria. (SCALARIID&.) Plate xxli. 

360. turtona, i J in. yellowish brown, ribs flat. 

361. communis, i in. cream, ridges raised. 

362. trevelyana, i in. fawn, ridges narrow, flat and white. 

363. dathratula, f in. white, ribs thin. 

364. pseudoscalaris, i in. cream, ridges raised sharply, basal keel. 

Scaphander. (SCAPHANDRID^.) Plate xxx. 

558. lignarius, 2jin. x i^in. shell striated. 

559. libranus, f in. x J in. shell with fine spiral, distinctly punctured 

grooves. 

Scissurella. (PLEUROTOMARIID^E.) Plate xxi. 

334. crlspata, fa in. whorls 4, flattened above, slit in margin of 

outer lip. 

Scrobicularia. (SCROBICULARIID&.} Plate viii. 
103. piperata, 2 in. x ij in. no lateral teeth. 

99. pnsmatica, fin. x fin. muscular scars irregular and indistinct, 
shell oblong. 

100. nitida, f in. x in. muscular scars oval and distinct, shell oval. 

101. alba, | in. x ^ in. inner edge toothed, shell oval. 

102. tenms, f in. x J in. inner edge bevelled and sharp, shell 

triangular. 



Scyllsea. (SCYLLJEID&.) Plate xxxii. 
600. pelagica, 



in. cream and transparent, height greater than 
breadth. 



GENERA AND SPECIES. 



I 39 



Siphonodentalium. (DENTALIID^.} Plate xv. 
184. lofotense, in. shell tapering, base with 4 notches. 



Skenea. (SKENEID&. 
434. planorbis, 



Plate xxiv. 
in. umbilicus 



a wide funnel 
interior of the spire. 



showing the 



Solecurtus. (SOLENIDsE.) 
146. candidus, 2 in. x ^ in. 
150. antiquatus, 2% in. x i in. 



Plate xiii. 

yellowish white, cardinal teeth blunt. 

chalky white, cardinal teeth jagged at their 
crowns. 



Solen. (SOLENIDJE.) Plate xiii. 
152. pellucidus, ij in. x f in. shell curved and thin. 



153. 

154. 



ensis, 
siliqua, 



155 vagina, 



3f in. x J in. shell curved and tubular. 

8 in. x i in. shell straight and tubular, 
cardinal and lateral teeth. 



hinge with 



shell straight and tubular, hinge with one 
tooth in each valve. 



Sphserium. (CYR^ENIDM.) Plate vii. 



81. corneum, 



82. lacustre, in. x 



yellowish horn-colour with faint concentric 
bands. 



. yellowish white or ashy grey, thin, com- 
pressed, sides truncated and sloping from 
dorsal margin. 

83 ovale, f in. x f in. drab or yellowish, anterior side rounded, 
posterior side truncated. 

84. rivicola, ^j in. X ^ in. horn-colour with dark concentric bands and 
deep ridges, ligament very conspicuous. 



Spirialis. (LIMACINID&.} 
583. retroversus, $ in. 



Plate xxx. 

shell silvery, almost transparent, and very 
thin. 



Stilifer. (EULIMIDJE.) Plate xxv. 
467. turtoni, J? in. spire in two parts, a cylinder and a point. 



Succlnea. (SUCCINEID^E.) Plate xx. 



317. virescens, 
315. pfeifferi, 
314. oblonga, 

313. elegans, 



in. greenish yellow, pillar whitish. 
in. whorls 3, shell curved at the ends. 

in. light horn-coloured, whorls 4, sutura 
oblique and very deep. 

in. oblong, amber-coloured, whorls 3 or 4, 
suture very oblique but not deep. 



140 GENERA AND SPECIES. 

316. putris, g in. oval, whorls 3 or 4, mouth oval and two- 

thirds length of shell, suture rather oblique 
and very deep. 

There are over twenty named varieties of the species of Succinca, but none of them 
differ conspicuously from the type. 

Tapes. (VENERW&.) Plate x. 

123. aiireus, i| in. x ij in. striations concentric; yellowish, streaked 

and blotched with brown and purple ; 
anterior laterals sunken but distinct. 

124. virgineus, i-f in. x if in. striations concentric; yellowish, rayed and 

spotted with reddish brown ; laterals 
indistinct. 

125. pullastra, if in. x i| in. striations radial and faint; whitish, rayed 

and streaked with browns and purples ; 
laterals ridge-like and indistinct. 

126. dccussatus, 2 in. x if in. striations radial and strong ; yellowish, with 

rays and streaks of brown. 

Tectura. (ACM&IDJE.} Plate xxi. 

319. lestudinalis, J in. inside pearly, central scar chocolate. 

320. virginea, $ in. inside porcelain white, central scar white. ' 

321. fulva, % in. inside orange. 

Tellina. (TELLINIDJE.) Plate viii. 

go. balaustina, 4 in. x in. shell equilateral and not grooved, inside 
tinged with orange. 

91. crassa, 2 in. x i| in. shell equilateral and grooved, inside tinged 

with rose. 

92. balthica, $ in. x ^ in. shell pointed at posterior end, margin 

rounded in front, hinge line curved. 

93. tennis, i in. x in. shell pointed at posterior end, margin not 

rounded in front, hinge line angular. 

94. fabula, | in. x ^ in. white, with or without a tinge of yellow. 

95. squalida, if in. x i in. orange, often with a red mark near the beaks. 

96. donacina, i in. x f in. shell angulated and thin, colour white and 

pink with a streak below the beak ; posterior 
lateral removed from the beak. 

97. pusilla, J in. x J in. shell angulated and convex, colour white 

and pink, with a streak below the beak. 

Teredo. (TEREDINIDJE.) Plate xiv. 

166. norvegica, sheath 12 in. pallets large, blades wedge-shaped in front. 

167. navalis, sheath 6 in. pallets small, blade forked and excavated 

on its outer edge. 

168. pedicellate, sheath : ]; in. pallets with middle part oval, outer part 

square. 



GENERA AND SPECIES. 14! 

169. megotara, sheath 6 in. pallets oval, outside front cuneiform and 

excavated. 

170. malleolus, sheath 3 in. pallets short with a broad blade. 

171. bipinnata, sheath 3 in. pallets with funnel joints. 



Testacella. (TESTACELLTDM.) Plate xviii. 

230. haliotidea, ^ in. shell ear-shaped, animal yellowish brown 



231. inaugei, 



with spots. 
in. shell cylindrical, animal dark brown. 



Thecacera. (POLYCERlDjE.} Plate xxxiii. 

607. pennigera, $ in. white, blotched with black and orange. 

virescens, $ in. pale pink, blotched with green. 

capitata, % in. white, spotted with greenish brown. 

Thracia. (ANATINIDM.) Plate xv. 

174. prtf tennis, ij in. x in. white, anterior margin semicircular. 

175. papyracea, i in. x & in. white, anterior margin gently curved. 

176. pubescens, 3 in. x 2 in. sandy, anterior margin gently curved. 

177. convexa, 2$ in. x 2 in. pale brown, margin indented on posterior 

side, beaks inflected to posterior side, inside 
yellowish. 

178. distoi-ta, f in. x T 9 5 in. white, posterior half angulated and generally 

longer than anterior, beaks inflected to 
posterior side, inside cream colour. 

Torellia. (TRICHOTROPID^E.) Plate xxiii. 
381. vestita, in. white, whorls 5 or 6, rapidly increasing in 



Tornatinus. (TORN AT IN ID &.} Plate xxx. 

551. mammillatus, ^ in. whorls 2 or 3, spire rimmed, pillar short and 

curved, fold indistinct. 

552. truncatulus, % in. whorls 3 or 4, spire rimmed, pillar short 

and flattened, fold strong. 

553. oblusus, % in. whorls 4, angulated at top, spire not 

rimmed, pillar broad and curved, fold 
indistinct. 

554. ventrosus, in. whorls 3, angulated at top, spire flat, pillar 

slight and curved, fold indistinct, outer 
corner of mouth rounded. 

555. expansus, * in. whorls 3 or 4, angulated at top, spire 

abruptly truncated, pillar straight above 
and curved below, fold obscure, outer 
corners of mouth angulated. 



142 GENERA AND SPECIES. 

556. hyalinus, ^ in. whorls 3 or 4, angulated on top, spire trun- 

cated, pillar straight above and curved 
below, fold obscure, outer corner of mouth 
angulated, outer lip bent at a third of its 
length from the top. 

557- globosus, \ in. whorls 3, tumid; spire truncated. 

Trichotropis. (TRICHOTROPIDJE.) Plate xxiii. 

380. borealis, f in. shell turreted, whorls 7, convex and ribbed, 

basal groove angular. 

Triopa. (POLYCERID&.} Plate xxxiii. 
606. claviger, f in. body white, gills white, tipped with yellow. 

Triton. (TRITONIDJE.) Plate xxv. 

459. nodiferus, 6 in. whorls 8 to 10, inside of outer lip with one 

row of ritiges. 

460. cutaceus, 2 in. whorls 5 or 6, body whorl with crested rib, 

inside of outer lip with 2 rows of ridges, 
having excavations along the inner row. 

Tritonia. (TRITON 'IIDJE.) Plate xxxii. 
602. hombergi, 5 in. head veil bilobed and fringed. 

alba, f in. head veil bilobed, with irregular points. 

plebeia, i in. head veil almost entire, with from 6 to 

8 points. 

lineata, f in. head veil entire, with 4 points. 



Trochus. (TROCHIDJE.) Plate xxii. 
Without umbilicus 
Over f in. 

352. granulatus, 1% in. shell dilated and rounded at the base. 

353. sizyphinus, i in. shell regularly pyramidal. 

Under f in. 
351. millegranus, fin. marked with rows of granules. 

349. striatus, $ in. inside silvery, with rib near margin, suture 

indistinct. 

350. exasperatus, J in. inside silvery, with rib near margin, basal 

ridge encircling each whorl.suture indistinct. 

348. montacuti, $ in. inside silvery, without rib near margin, 

suture distinct. 

With umbilicus 

Under J in. 

340. glancus iV in - whorls 4. 

338. helicinus, J in. whorls 5, umbilicus narrow but deep. 



GENERA AND SPECIES. 143 

346. duminyi, % in. whorls 5 ; umbilicus extended over base of 

shell. 
339- granlandtcus, in. whorls 6. 

Over ^ in. 

354. occidentalis, whorls 7 or 8 ; shell opaline and pyramidal. 

341. amabilis, in. whorls 7; shell white and pyramidal. 

342. magus, % in. whorls 8 ; shell white, variegated with red, 

a depressed cone, thick and rounded. 

343. tumidus, J in. whorls 6 or 7 ; shell white, speckled with 

brown and turreted. 

344. cinerarius, % in. whorls 6 or 7 ; shell grey, finely reticulated 

and conical. 

345. umbilicatus, in. whorls 6 or 7 ; shell grey with pink reticu- 

lations and conical. 

347. lincatus, i in. whorls 6; shell greenish grey with purple 

reticulations, thick, rounded and conical. 

Trophon. (MURICIDjE.) Plate xxvi. 

503. muricatus, f in. canal long, whorls 7 or 8, angulated and 

flattened above. 

504. barvicensis, f in. canal long, whorls 7 or 8, bearing spines 

above. 

505. truncatus, f in. canal short, whorls 6 or 7, rounded. 

Truncatella. (TRUNCATELLIDJE.) Plate xxiii. 
399. truncatula, $ in. shell short, cylindrical and turreted. 

TurriteUa. (TURRITELLID&.) Plate xxv. 

452. terebra, 2% in. shell a long close spiral with an angulated 

base. 

Unio. (UNIONID&.} Plate vi. 

55. margaritifer, 5 in. x 2f in. oblong, lower margin straight. 

56. pictorum, 3 in. x ij in. oblong, beaks with small tubercles not con- 

fluent, anterior teeth compressed and 
crenulated. 

57. tumidus, 3 in. x ij in. oval, beaks with angular wrinkles, confluent 

and concentric, lower margin curved. 

Valvata. (VALVATID&.) Plate xxiv. 

441. cristata, in. whorls 5, shell a flat coil. 

442. piscinalis, in. whorls 6, shell a broad cone. 

Velutina. (LAMELLARIID&.) Plate xxiii. 
378. plicatilis, % in. whorls 2^, sculpture indistinct. 

379 Icsvigata, f in. whorls 31, sculpture distinct. 

Venerupis. (VENERID&.} Plate x. 
127 irus, i in. x \ in. shell having thin concentric ridges. 



144 



GENERA AND SPECIES. 



Venus. (YEN BRIDGE.} Plate ix. 



114. exoleta, . 2 in.^x 2 in. 



115. lincta, i| in. x i| in. 



116. chione, 3 in. x 2f in. 



117. fasciata, ^ in. x fin. 



118. casina, if in. x if in. 



119. verrucosa,2in. x i? in. 



121. gallina, ij in. x i^ in. 



120. ovala, 



n. x 



n. 



inside margin plain, colour yellowish white, 
rayed with white and pink, inside polished 
and freckled, with or without a purple stain. 

inside margin plain ; colour white, with 

yellow, brown, and pink ; inside chalky 

white. 

inside margin plain, colour rich pinkish 

brown with rays of darker brown, inside 

chalky white. 

inside margin notched except on the posterior 
side, colour pinkish with pink rays, ribs 
concentric and flat, margins angled. 

inside margin notched except on the posterior 
side, ridged with concentric plates, colour 
yellowish white with or without brown rays, 
margins rounded. 

inside margin notched except on the posterior 
side, coarsely ribbed concentrically, colour 
yellowish brown with brown rays, mouth 
white, inside white, margins rounded. 

inside margin notched except on the posterior 
side, finely striated concentrically, colour 
pale brown with darker rays, margins 
obliquely rounded. 

inside margin notched all round. 



Vertigo. (PUPIDM.) Plate xx. 

Shell sinistral 

293. angustior, ^ g in. teeth 4 or 5, mouth triangular. 

299. pusilla, ^ in. teeth 6 or 7, mouth square. 

Shell dextral 
No teeth 

295. edentula, ^ in. faintly striated. 

297. minutissima, ^ in. distinctly striated. 

Teeth 4 or 5 
With rib- 

296. hlljcborgii, ^ in. rib thin. 

298. motilinsiana, ^ in. rib very stout, umbilicus open. 



300. pygmaa, 

292. alpestris, 

301. substriata, 

302. tumida, 
294. antivertigo, 



^ in. rib very stout, umbilicus narrow. 
Without rib 

^ in. suture very deep. 
Teeth 6 

^ in. yellowish horn-coloured, suture very deep, 
mouth semi-oval. 

^ in. mouth heart-shaped. 
^ in. mouth triangular. 



GENERA AND SPECIES. 



Vitriua. (HELICIDM.} Plate xix. 
247. pellucida, in. shell thin and green, no umbilicus. 



Viviparus. (VIVIPARID&.\ 

439. contecta, i in. 

440. vivipara, ij in. 



Plate xxiv. 

whorls 7, much rounded ; suture deep, 
umbilicus deep. 

whorls 6, rather convex ; suture shallow, 
umbilicus very slight. 

Xylophaga. (PHOLADID^.} Plate xiv. 

165. dorsalis, in. x ^ in. shell gaping widely anteriorly, apophysis of 
the right valve larger than that of the left. 



Zonites. (HELICIDM. 

248. draparnaldi, 



Plate xix. 
in. whorls 6 or 7 



striated transversely, fawn 
above, bluish white below ; mouth oval and 
very oblique, umbilicus wide, animal cobalt 
blue. 

257. purus, ^ in. whorls 4, body whorl half of shell ; circular 

striae, umbilicus narrow and deep. 

258. radiatulus, in. whorls 4 or 4^, striae extending from whorl 

to whorl and not interrupted by sutures, 
mouth semilunar and oblique, umbilicus 
moderately deep. 

256. nitidulus, in. whorls 4 or 5, striae interrupted by the 

sutures, spire slightly produced, mouth 
oblique or small. 

254 crystallinus, -fa in. whorls 4^ to 5, body whorl same as pre- 

ceding whorl, mouth lunate, umbilicus 
small. 

255. nitidus, % in. whorls 5, shell sub-globose and brownish, 

mouth oblique and roundish, umbilicus 
narrow and deep. 

249. alliarius, \ in. whorls 5, last whorl moderately large, 

exposing second whorl, mouth semilunar 
and narrow. 

254. glabcr, ^ in. whorls 5 or 5^, body whorl occupying half 

of shell, which is thin, glossy, compressed, 
transversely striated and dark horn-coloured; 
mouth three-quarters of a circle, umbilicus 
narrow and deep. 

252. excavatus, J in. whorls 5^, shell thin and horn-coloured, 

mouth small and lunate, umbilicus large, 
disclosing all the whorls. 

253. fulvus, T V in. whorls 5^ or 6, shell keeled and conical. 

250. cellarius, f in. whorls 5 or 6, last whorl large ; shell pale 

horn-colour, mouth crescent shaped, um- 
bilicus large, exposing second whorl. 



CHAPTER XIII. 

LIST OF SPECIES, 



THE numbers refer to the coloured plates. The unnumbered 
names are those of the unfigured species of sea-slugs. 
The genera will be found alphabetically arranged in the pre- 
ceding chapter. 



Abbreviata, Nesera, 180 
Abyssicola, Rissoa, 408 
Abyssorum, Dentalmm, 189 
Acicula, Achatina, 312 
Acicula, Odostomia, 501 
Aciculatus, Murex, 507 
Aculeata, Helix, 263 
Aculeatum, Cardium, 129 
Acuminata, Cylichna, 560 
Acuta, Odostomia, 478 
Acuta, Physa, 227 
Acutus, Bulimus, 259 
Adelaidae, ^Eolis, 
Adriaticus, Mytilus, 22 
/Estuarii, Littorina, 391 
Affinis, Natica, 376 
Agrestis, Limax, 235 
Alba, ^Eolis, 
Alba, Cylichna, 564 
Alba, Scrobicularia, 101 
Alba, Tritonia, 
Albella, Odostomia, 473 
Albella, Rissoa, 413 
Albus, Chiton, 195 
Albus, Planorbis, 215 
Alderi, ^Eolis, 
Alderi, Natica, 374 
Alliarius, Zonites, 249 
Alpestris, Vertigo, 292 
Arnabilis, Trochus, 341 
Amnicum, Pisidium, 85 
Amoena, /Eolis, 
Anatina, Anodonta, 58 
Ancyloides, Propilidium, 323 
Angulata, ^Eolis, 
Angulata, Philine, 571 
Angustior, Vertigo, 293 
Antiquatus, Solecurtus, 150 
Antiquus, Fusus, 520 
Antivertigo, Vertigo, 294 



Aperta, Philine, 576 
Aratus Pecten, 41 
Arborescens, Dendronotus, 

% 599 

Arborum, Limax, 238 
Arbustorum, Helix, 264 
Arenaria. Mya, 143 
Arenicola, /Eolis, 
Ascaris, Aclis, 366 
Aspera, Doris, 670 
Aspersa, Helix, 265 
Aspersa, Idalia, 
Ater, Arion, 241 
Atornus, Homalogyra, 385 
Attenuata, Pleurotoma, 537 
Aurantiaca, ^Eolis, 
Aureus, Tapes, 123 
Auricularia, Limnaea, 207 
Aurita, Limopsis, 17 

Balaustina, Tellina, 90 
Balthica, Tellina, 92 
Barbatus, Mytilus, 21 
Barleei, Cerithiopsis, 448 
Barvicensis, Trophon, 504 
Berniciensis, Fusus, 527 
Bidentata, Montacuta, 70 
Bidentatus, Melampus, 202 
Bifida, Hermsea, 
Bilamellata, Doris 
Bilineata, Eulima, 466 
Binghami, Mya, 145 
Bipinnata, Teredo, 171 
Biplicata, Clausilia, 304 
Borealis, Limopsis, 18 
Borealis, Lucina, 62 
Borealis, Trichotropis, 380 
Bourguignati, Arion, 242 
Brachystoma, Pleurotoma, 540 
Bullata, Acera, 568 



146 



LIST OF SPECIES. 



Calathus, Rissoa, 403 
Cancellata, Emarginula, 332 
Cancellata, Rissoa, 402 
Cancellatus, Chiton, 193 
Candida, Pholas, 161 
Candidus, Solecurtus, 149 
Cantiana, Helix, 266 
Caperata, Helix, 267 
Capitata, Thecacera, 
Carinata, Pleurotoma, 145 
Carinatus, Planorbis, 216 
Carnea, ^Eolis, 
Cartusiana, Helix, 268 
Casina, Venus, 118 
Castanea, Goniodoris, 694 
Castaneum, Amphidesma, 107 
Catena, Natica, 373 
Catena, Philine, 570 
Cellarius, Zonites, 250 
Celticum, Onchidium, 318 
Chinensis, Calyptraea, 383 
Chione, Venus, 116 
Cimicoides, Rissoa, 405 
Cinerarius, Trochus, 344 
Cinereus, Chiton, 194 
Cinereo-niger, Limax, 240 
Cingillus, Rissoa, 424 
Cingulata, ^Eolis 
Clarkiae, Lepton, 79 
Clathrata, Odostomia, 489 
Clathratula, Scalaria, 363 
Claviger, Triopa, 606 
Clavula, Odostomia, 471 
Coccinea, Doris, 
Cocksii, Actaeonia, 
Coeca, Lepeta, 322 
Coerulea, ^Eolis, 
Communis, Scalaria, 361 
Complanatus, Planorbis, 217 
Compressa, Astarte, 51 
Concinna, yEolis, 
Concinna, Helix, 269 
Conoidea, Odostomia, 476 
Conspicua, Odostomia, 479 
Contecta, Viviparus. 439 
Contortus, Planorbis, 218 
Convexa, Thracia, 177 
Cor, Isocardia, 54 
Corneum, Sphaerium, 81 
Corneus, Planorbis, 219 
Coronata, Doto, 
Coronata, ^Eolis, 
Corrugata, Actaeonia, 
Costata, Pleurotoma, 538 
Costata, Rissoa, 410 
Costellata, Neaera, 181 
Costulaia, Cerithiopsis, 451 



Costulata, Modiolaria, 27 
Costulata, Psammobia, 140 
Costulata, Rissoa, 416 
Couchii, yEolis, 
Crassa, Emarginula, 331 
Crassa, Tellina, 91 
Crassior, Lacuna, 392 
Crispata, Pholas, 163 
Crispata, Scissurella, 334 
Cristata, Ancula, 695 
Cristata, Antiopa, 
Cristata, Valvata, 441 
Croulinensis, Axinus, 67 
Crystallinus, Zonites, 251 
Cuspidata, Doto, 
Cuspidata, Neaera, 183 
Cutaceus, Triton, 460 
Cutlerianum, Cyclostrema, 335 
Cycladia, Kellia, 74 
C.ygnea, Anodonta, 59 
Cylindracea, Cylichna, 563 

Dactylus, Pholas, 160 
Dalei, Buccinopsis, 519 
Decussata, Crenella, 25 
Decussata, Odostomia, 488 
Decussatus, Tapes, 126 
Dendritica, Hermaea, 
Depilaus, Aplysia, 578 
Depressa, Doris, 
Depressa, Limapontia, 591 
Despecta, ^Eolis, 
Diaphana, Doris, 
Diaphana, Jeffreysia, 435 
Diaphana, Odostomia, 484 
Distorta, Eulima, 463 
Distorta, Thracia, 178 
Dilatatus, Planorbis, 220 
Discors, Modiolaria, 28 
Discrepans, Chiton, 191 
Divaricata, Lacuna, 393 
Divaricatus, Loripes, 64 
Dolioformis, Odostomia, 487 
Donacina, Tellina, 96 
Dorsalis, Xylophaga, 165 
Draparnaldi, Zonites, 248 
Drummondi, yEolis, 
Dubia, Gastrochsena, 346 
Duminyi, Trochus, 346 

Echinatum, Cardium, 130 
Edentata, Vertigo, 295 
Edule, Cardium, 136 
Edulis, Mytilus, 19 
Edulis, Ostrea, 32 
Elegans, /Eolis, 
Elegans, Bulla, 566 



148 



LIST OF SPECIES. 



Elegans, Cyclostoma, 397 
Elegans, Idalia, 
Elegans, Succinea 313 
Eliiptica, Lima, 45 
Elliptica, Lutraria, 147 
Eliiptica, Mactra, 109 
Ensis, Solen, 153 
Entalis, Dentalium, 187 
Ephippium, Anomia, 9 
Ericetorum, Helix, 270 
Erinaceus, Murex, 506 
Europaea, Cypraea, 457 
Exasperatus, Trochus, 350 
Excavata, Odostomia. 495 
Excavatus, Zonites, 252 
Exigua, ^Eolis, 
Exigua, lanthina, 359 
Exiguum, Cardium, 133 
Eximia, Odostomia, 493 
Exoleta, Venus, 114 
Expansus, Toratinus, 555 

Fabula, Tellina, 94 
Farrani, ^Eolis, 
Fasciata, Venus, 117 
Fasciatum, Cardium, 134 
Fascicularis, Chiton, 190 
Fenestrata, Odostomia, 494 
Fenestratus, Fusus, 528 
Ferroensis, Psammobia, 141 
Ferruginosa, Montacuta, 72 
Ferruginosus, Axinus, 68 
Fissura, Emarginula, 329 
Flammea, Doris, 
Flavidus, Lomanotus, 647 
Flavus, Arion, 243 
Flavus, Limax, 234 
Flexuosus, Axinus, 66 
Fluviatilis, Ancylus, 206 
Fluviatilis, Neritina, 356 
Fontinale, Pisidium, 86 
Fontinalis, Physa, 228 
Formosa, Hero, 596 
Fornicata, Crepidula, 384 
Fragilis, Doto, 
Fragilis, Gastrana, 98 
Fragilis, lanthina, 357 
Fulgida, Rissoa, 421 
Fulva, Tectura, 321 
Fulvus, Zonites, 253 
Fusca, Helix, 271 

Gagates, Amalia, 232 
Galerita, Pleurotoma, 541 
Gallina, Venus, 121 
Gibba, Corbula, 146 
Gibba, Fissurella, 327 



Glaber, Planorbis, 221 
Glaber, Zonites, 254 
Glabra, Limnasa, 208 
Glabrum, Caecum, 454 
Glauca, ^Eolis, 
Glauca, Mactra, 112 
Glaucoides, yEolis, 
Glaucus, Trochus, 340 
Globosus, Tornatinus. 557 
Globularis, Jeffreysia, 437 
Glottensis, /Eolis. 
Glutinosa, Limnasa, 209 
Glycimeris, Pectunculus, 16 
Goodallii, Bulimus, 260 
Gracilis, /Eolis, 
Gracilis, Fusus, 524 
Gracilis, Mangilia, 531 
Granulata, Poromya, 179 
Granulatus, Trochus, 352 
Grayana, Assiminea, 432 
Grayi, Embletonia, 
Graeca, Fissurella, 326 
Grosnlandica, Natica, 371 
Grosnlandicus, Trochus, 339 
Gulsonae, Aclis, 3 69 

Haemastomia, Purpura, 509 
Haliaeeti, Columbella, 511 
Haliotidea, Testacella, 230 
Hancocki, Runcina, 582 
Hanleyi, Chiton, 192 
Helicinus, Trochus, 338 
Hians, Lima, 48 
Hispida, Helix, 272 
Hirundo, Avicula, 30 
Hombergi, Tritonia, 
Hortensis, Arion, 244 
Hortensis, Helix, 273 
Humphreysianum, Buccinum, 

518 

Hungaricus, Capulus, 382 
Hya-lina, Antiopa, 644 
Hyalinus, Tornatinus, 556 
Hydatis, Bulla, 565 
Hypnorum, Physa, 229 

Insequalis, Idalia, 
Inaequivalvis, Pandora, 172 
Inconspicua, Doris, 
Inconspicua, Rissoa, 412 
Incrassata, Nassa, 515 
Indistincta, Odostomia, 490 
Inornata, ^Eolis, 
Insculpta, Odostomia, 483 
Intermedia, Eulima, 462 
Interstincta, Odostomia, 491 
Involuta, Limnaea, 210 



LIST OF SPECIES. 



I 49 



Irus, Venerupis, 127 
Islandica, Cyprina, 53 
Is-landica, Natica, 370 
Islandicus, Fusus, 523 

Jeffreysii, Rissoa, 406 
effreysianus, Fusus, 526 
effreysii, Cadulus, 186 
enkinsii, Hydrobia, 429 
ohnstoni, Doris, 

Lactea, Area, 13 
Lactea, Odostomia, 498 
Lactea, Rissoa, 401 
Lacteus, Loripes, 63 
Lacustra, Sphaerium, 82 
Lacustris, Ancylus, 205 
Lsevigata, Pleurotoma, 543 
Laevigata, Velutina, 379 
Laevis, Chiton, 198 
Laevis, Limax, 236 
Laevis, Marginalia, 529 
Lamellata, Helix, 274 
Laminata, Clausilia, 305 
Landsburgi, yolis, 
Lapicida, Helix, 275 
Lapillus, Purpura, 508 
Leachii, Bithynia, 430 
Leachii, Idalia, 
Legumen, Ceratisolen, 151 
Lessoni, Polycera, 
Leufroyi, Mangilia, 532 
Librarius, Scaphander, 559 
Lignarius, Scaphander, 558 
Lilljeborgii, Vertigo. 296 
Limacina, CHone, 585 
Lincta, Venus, 115 
Linearis, Mangilia, 533 
Lineata, . Acicula, 398 
Lineata, yolis, 
Lineata, Tritonia, 
Lineatus, Planorbis, 222 
Lineatus, Trochus, 347 
Littorea, Littorina, 390 
Littorina, Assiminea, 433 
Lofotense, Siphonodentalium, 184 
Loscombii, Lima, 47 
Loveni, Doris, 
Loveni, Pleurophyllidia, 656 
Lubrica, Cochlicopa, 310 
Lucida, Leda, 6 
Lukisi, Odostomia, 472 

Macandrese, Aporrhai's, 456 
Maculosus, Geomalacus, 246 
Magus, Trochus, 342 
Malleolus, Teredo, 170 



Mammillatus, Tornatinus, 551 
Margaritifer, Unio, 55 
Marginata, Amalia, 233 
Marginata, Pupa, 288 
Marginatus, Chiton, 196 
Marmoratus, Lomanotus, 
Marmorata, Modiolaria, 26 
Marmoreus, Chiton, 199 
Maugei, Testacella, 231 
Maximus, Limax, 239 
Maximus, Pecten, 43 
Megotara, Teredo, 169 
Melanopus, Aplysia, 579 
Membranacea, Rissoa, 414 
Membranaceus, Pleurobranchus, 

580 

Metaxa, Cerithiopsis, 450 
Metula, Cerithium, 443 
Millegrana, Doris, 
Millegranus, Trochus, 351 
Minima, Circe, 113 
Minima, Lachesis, 510 
Minima, Odostomia, 468 
Minimum, Cardium, 137 
Minimum, Carychium, 201 
Minuta, Embletonia, 
Minuta, Leda, 7 
Minutissima, Vertigo, 297 
Minutum, Cyamium, 49 
Modesta, Alderia, 587 
Modiolus, Mytilus, 20 
Montacuti, Natica, 375 
Montacuti, Trochus, 348 
Mont-anus, Bulimus, 261 
Moulinsiana, Vertigo, 298 
Mucroniferous, Proctonotus, 594 
Muricata, Doris, 
Muricatus, Trophon, 503 
Myosotis, Melampus, 203 



Nassa, 
Nassa, Columbella, 512 
Nautileus, Planorbis, 223 
Navalis, Teredo, 167 
Nebula, Pleurotoma, 542 
Nemoralis, Helix, 276 
Neritoides, Littorina, 388 
Nitens, Cyclostrema, 336 
Nitida, Nassa, 514 
Nitida, Nucula, 3 
Nitida, Philine, 575 
Nitida, Scrobicularia, TOO 
Nitidissima, Odostomia, 520 
Nitidula, Cyclichna, 561 
Nitidulus, Zonites, 256 
Nitidum, Lepton, 77 
Nitidum, Pisidium, 87 



'50 



LIST OF SPECIES. 



Nitidus, Planorbis, 224 
Nitidus, Zonites, 255 
Nigra, Limapontia, 
Nigra, Modiolaria, 29 
Nivalis, Pleurotoma, 544 
Nivosa, Odostomia, 469 
Noachina, Puncturella, 328 
Nobilis, Fiona, 593 
Nodiferus, Triton, 459 
Nodosa, Goniodoris, 
Nodosum, Cardium, 135 
Nodulosa, Area, 15 
Northumbrica, ^Eolis, 
Norvegica, Lyonsia, 173 
Norvegica, Saxicava, 156 
Norvegica, Teredo, 166 
Norvegicum, Cardium, 138 
Norvegicus, Fusus, 521 
Nucleus, Nucula, 2 

Obliqua, Area, 12 
Obliqua, Odostomia, 485 
Oblonga, Doris, 
Oblonga, Lutraria, 148 
Oblonga, Succinea, 314 
Obscurus, Bulimus, 262 
Obtusata, Littorina, 387 
Obtusus.Tornatinus, 553 
Obvoluta, Helix, 277 
Occidentalis, Trochus, 354 
Ocellata, Polycera, 
Olivacea, oEolis, 
Opalina, Jeffreysia, 436 
Opercularis, Pecten, 35 
Otis, Otina, 204 
Ovale, Sphaerium, 83 
Ovata, Venus, 120 

Pallida, Embletonia, 
Pallida, Odostomia, 475 
Pallidula, Lacuna, 396 
Palustris, Limnaea, 211 
Papillata, Crimora, 608 
Papillosa, ^Eolis, 
Papillosum, Cardium, 132 
Papyracea, Pholadidea, 164 
Papyracea, Thracia, 175 
Parva, Pholas, 162 
Parva, Rissoa, 411 
Parvula, Clausilia, 308 
Patelliformis, Anomia, 10 
Patula, Ovula, 458 
Peachii, ^Eolis, 
Pectunculoides, Area, n 
Pedicellata, Teredo, 168 
Pelagica, Scyllasa, 655 
Pellucida, ^Eolis, 



Pellucida, Vitrina, 247 
Pellucidum, Helcion, 325 
Pellucidus, Solen, 152 
Pennigera, Thecacera, 
Peregra, Limnaea, 212 
Pernula, Leda, 8 
Perspicua, Lamellaria, 377 
Perversa, Balea, 303 
Perversum, Cerithium, 445 
Pes-pelecani, Aporrhais, 455 
Pfeifferi, Succinea, 315 
Phaseolinus, Mytilus, 23 
Pholadiformis, Petricola, 128 
Picta, /Eolis, 
Pictorum, Unio, 56 
Pilosa, Doris, 
Pinnatifida, Doto, 
Piperata, Scrobicularia, 103 
Piscinalis, Valvata, 442 
Planorbis, Skenea, 434 
Plebeia, Tritonia, 
'Plicata, Odostomia, 482 
Plicata, Panopaea, 158 
Plicatilis, Velutina, 378 
Plumella, Pleurobranchus, 581 
Polita, Eulima, 461 
Politus, Donax, 106 
Polymorpha, Dreissensia, 60 
Pomatia, Helix, 279 
Portlandicus, Lomanotus, 
Praetenuis, Thracia, 174 
Prismatica, Scrobicularia, 99 
Propinquus, Fusus, 525 
Proxima, Doris, 
Proxima, Rissoa, 418 
Pruinosa, Philine, 574 
Pseudo-scalaris, Scalaria, 364 
Pubescens, Thracia, 176 
Pulchella, Cerithiopsis, 449 
Pulchella, Helix, 280 
Pulchella, Idalia, 
Pulcherrima, Rissoa, 420 
Pulchra, Embletonia, 
Pulla, Phasianella, 355 
Pullastra, Tapes, 125 
Pisana, Helix, 278 
Punctata, ^Eolis, 
Punctata, Aplysia, 577 
Punctata, Philine, 573 
Punctilucens, ^Egirus, 605 
Punctura, Rissoa, 407 
Purpurascens, ^Eolis, 
Purpurea, Mangilia, 535 
Purus, Zonites, 257 
Pusilla, Doris, 
Pusilla, Odostomia, 499 
Pusilla, Tellina, 97 



LIST OF SPECIES. 



Pusilla, Vertigo, 299 
Pusillum, Pisidium, 88 
Pusio, Pecten, 33 
Pustulata, yEolis, 
Puteolus, Lacuna, 395 
Putris, Succinea, 316 
Pygmasa, Helix, 281 
Pygmasa, Leda, 5 
Pygmaea, Nassa, 516 
Pygmaea, Vertigo, 300 
Pyramidata, Clio, 584 

Quadrangulata, Doris, 
Quadrata, Philine, 572 
Quadricornis, Idalia, 
Quadrilineata, Polycera, 

Radiatulus, Zonites, 258 
Repanda, Doris, 
Reticulata, Mangilia, 534 
Reticulata, Nassa, 513 
Reticulata, Rissoa, 404 
Reticulatum, Cerithium, 444 
Retroversus, Spirialis, 583 
Revelata, Helix, 282 
Rhombea, Crenella, 24 
Ringens, Pupa, 289 
Rissoides, Odostomia, 474 
Rivicola, Sphaerium, 84 
Rolphii, Clausilia, 306 
Rosea, Emarginula, 330 
Roseum, Pisidium, 89 
Rostrata, Ne.3era, 182 
Rota, Homalogyra, 386 
Rotundata, Diplodonta, 65 
Rotundata, Helix, 283 
Rotundata, lanthina, 358 
Ruber, Chiton, 197 
Rubra, Barleeia, 425 
Rubra, Lasaea, 75 
Rudis, Littorina, 389 
Rudis, Pinna, 31 
Rufa, Odostomia, 497 
Rufa, Pleurotoma, 547 
Rufescens, Helix, 284 
Rufibranchiata, ^Eolis, 
Rugosa, Clausilia, 307 
Rugosa, Saxicava, 157 
Rugulosa, Pleurotoma, 539 
Rupestris, Helix, 285 



Sanguinea, ^ 
Sarsii, Lima, 44 
Scabra, Philine, 569 
Scabridus, Chiton, 200 
Scalaris, Odostomia, 496 
Scillae, Odostomia, 500 



Secale, Pupa, 290 
Semistriata, Rissoa, 423 
Septangularis, Pleurotoma, 546 
Septemradiatus, Pecten, 36 
Sericea, Helix, 286 
Serpuloides, Cyclostrema, 337 
Siliqua, Solen, 154 
Similis, Hydrobia, 427 
Similis, Pecten, 40 
Smaragdina, ^Eolis, 
Solida, Clausilia, 309 
Solida, Mactra, 108 
Soluta, Rissoa, 422 
Sordida, Natica, 372 
Sparsa, Doris, 
Spinifer, Lucina, 61 
Spiralis, Odostomia, 49 ->. 
Spirorbis, Planorbis, 225 
Squalida, Tellina, 95 
Squamosum, Lepton, 76 
Stagnalis, Limnaea, 213 
Stenostoma, Eulima, 464 
Stipata, yolis, 
Striata, Rissoa, 417 
Striatula, Rissoa, 400 
Striatus, Pecten, 39 
Striatus, Trochus, 349 
Striolata, Pleurotoma, 536 
Stultorum, Mactra, in 
Sub-auriculata, Lima, 46 
Sub-carinatus, Adeorbis, 438 
Subfuscus, Arion, 185 
Subfusiformis, Cadulus, 185 
Suborbicularis, Kellia, 73 
Substriata, Montacuta, 69 
Substriata, Vertigo, 301 
Sub-truncata, Mactra, no 
Subulata, Eulima, 465 
Sulcata, Astarte, 50 
Sulcata, Nucula, i 
Sulcatulum, Lepton, 78 
Supranitida, Aclis, 367 

Tarentinum, Dentalium, 188 
Tellinella, Psammobia, 139 
Tenella, Lacuna, 394 
Tenellus, Limax, 237 
Tentaculata, Bithynia, 431 
Tenuis, Nucula, 4 
Tenuis, Scrobicularia, 102 
Tenuis, Tellina, 93 
Terebra, Turritella, 452 
Teres, Mangilia, 530 
Testae, Pecten, 38 
Testudinaria, Doris, 
Testudinalis, Tectura, 319 
Tetragona, Area, 14 



152 



LIST OF SPECIES. 



Tigrinus, Pecten, 37 
Tornatilis, Actason, 550 
Trachea, Caecum, 453 
Trevelyana, Pleurotoma, 549 
Trevelyana, Scalaria, 362 
Triangularis, Astarte, 52 
Tricolor, ^Eolis, 
Tridens, Cochlicopa, 311 
Truncata, Mya, 144 
Truncatula, Limnsea, 214 
Truncatula, Odostomia, 470 
Truncatula, Truncatella, 399 
Truncatulus, Tornatinus, 552 
Truncatus, Trophon, 505 
Trunculus, Donax, 105 
Tubercularis, Cerithiopsis, 447 
Tuberculata, Doris, 
Tuberculata, Haliotis, 333 
Tuberculatum, Cardium, 131 
Tumida, Vertigo, 302 
Tumidula, Montacuta, 71 
Tumidus, Trochus, 343 
Tumidus, Unio, 57 
Turricula, Pleurotoma, 548 
Turrita, Odostomia, 481 
Turtonae, Scalaria, 360 
Turtoni, Fusus, 522 
Turtoni, Galeomma, Ho 
Turtoni, Stilifer, 467 

Ulidiana, Doris, 
Ulvae, Hydrobia, 426 
Umbilicaris, Odostomia, 477 
Umbilicata, Cylichna, 562 
Umbilicata, Pupa, 291 
Umbilicatus, Trochus, 345 



Undata, Lucinopsis, 122 
Undatum. Buccinum, 517 
Unica, Aclis, 365 
Unidentata, Odostomia, 480 
Utriculus, Bulla, 567 

Vagina, Solen, 155 
Varius, Pecten, 34 
Ventrosa, Hydrobia, 428 
Ventrosus, Tornatinus, 554 
Verrucosa, Venus, 119 
Vespertina, Psammobia, 142 
Vestita, Torellia, 381 
Violacea, Rissoa, 415 
Virescens, Succinea, 317 
Virescens, Thecacera, 
Virgata, Helix, 287 
Virginea, Tectura, 320 
Virgineus, Tapes, 124 
Viridis, yEolis, 
Viridis, Elysia, 588 
Vitrea, Rissoa, 419 
Vitreus, Pecten, 42 
Vittata, yEolis, 
Vittatus, Donax, 104 
Vivipara, Viviparus, 440 
Vortex, Planorbis, 226 
Vulgata, Patella, 324 
Vulgatum, Cerithium, 446 

Walleri, Aclis, 368 
Warreni, Odostomia, 486 

Zetlandica, Doris, 
Zetlandica, Rissoa, 409 
Zizyphinus, Trochus, 353 



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UNIVERSITY OF CALIFORNIA LIBRARY 
BERKELEY 

Return to desk from which borrowed. 
This book is DUE on the last date stamped below. 



fiiology Librahf 



DEC 2 1951 

DEC 6 



LD 21-95m-ll,'50 (2877sl6)476