:-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 Mt 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.

0 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 THE 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 —
Cardium—ha.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,

4o

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 two—Otina.

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 — Diplodontay 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,

I73-

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 inch—Trophon, 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 left—fasciata — 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 isTpartially 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.

78

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.
Gastrochanat 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 ; Tapesl 123 to 126; Venernpist 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, 447-451-

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,
378. 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, 3I3-3*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, Jin- 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 2r1ir 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 Tm- 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 sl 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, Txff 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>oly°ona. — 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, £ jn. 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.
4f 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, % in- 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^0in. 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,
obtongat 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. adriaticust$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, £ iQ- 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.

in 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, i£in. 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.

sneH oval. sPire 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.

I39

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 T95 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, TV 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.

I49

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, y£olis,
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, y£olis,
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, y£olis,
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 20 1951

DEC 6

LD 21-95m-ll,'50 (2877sl6)476