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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