CONTENTS.

LETTER I.

Conchology a rational study, 1-3: necessary to the Geologist,

3, 4 important to the Naturalist, 4, 5.-Characters of the Mol-

lusca, 5, 6 of Cephalopods, 6: of Pteropods, 7: of Gasteropods,

7: of Conchifera, 7 of Tunicated Mollusca, 7: of Brachiopods,

7: of Cirrhopods, 7.-How to get enthusiasm in the study, 8.

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1

LETTER II.

The hurtful Mollusca; the Teredo, 9-12: the Slugs and Snails,

12, 13: monstrous Cephalopods, 13-15: the Aplysia, or Sea-hare, 16

-18: poisonous Mollusca, 18, 19: the Mussel, 20, 21: Oyster, 21, 22. 9

LETTER III.

Edible Mollusca, 23: dependence of animals on each other, 23,

24.-Mollusca food to quadrupeds, 24—26: to birds, 26-28: to fishes,

28, 29.-Mollusca used for baits, 29-31: food to insects, 31, 32:

food to man, 32.-The Oyster, 32, 33.-The British Oyster fishery,

33-35: the French fishery, 35, 36.-Oysters, 36. The Mussel

and Cockle, 37, 38: other edible bivalves, 38-40.-Periwinkles and

Whelks, 40, 41.-Mollusca, their use with savage nations, 42, 43.—

Edible Cephalopods, 43-45: Tunicata, 45: Snails, 45—48. .

23

LETTER IV.

The pearl Oyster, 49: Pearls, their estimation and value amongst

the Romans, 49–52: ancient Pearl fisheries, 52: Pearl fishery of

Ceylon, 53, 54: of the Red Sea, 54: of Britain, 54-58: of America,

58-62.-Shells worn as ornaments, 62, 63: economical use of shells,

63, 64: models for utensils and ornaments, 65, 66: used in religious

services, 66, 67: pilgrim shells, 67, 68.—The Pinna, 68: its silk, 68,

69 the Tyrian purple, 69-72: the dye of the Whelk, 72-74: the

Tyrian purple, 74, 75: China-ink, 76: Mother-of-pearl, 76, 77:

medicinal Mollusca, 77: their vulgar uses, 77, 78: their superstitious

applications, 79, 80.

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49

LETTER V.

The use of the dead shell to other animals, 81: the Hermit Lobster,

82, 83: the Spider, 83, 84: the Siphunculus, 84: insects and worins, 84:

the Nautilus, 84-86.

81

LETTER VI.

The Mollusca in their relations to dead matter: the Teredo, 87:

saxicavous Mollusca, 88, 89: the origin of lime, 89-91: the creation

and succession of the Mollusca, 91-94: tertiary formations, 94: recent

formations, 94-96: checks to the increase of Mollusca, 97–98.

LETTER VII.

An exposition of Cuvier's arrangement of the Mollusca: the cha-

racter of Mollusca, 100, 101: their classes; viz., Cephalopods, 101 :

Pteropods, 101: Gasteropods, 101: Acephales, 101, 102: Brachiopods,

102: Cephalopods, order and families, 102, 103: Pteropods, their

genera, 104: Gasteropods, their orders, 104: Pulmones, 105: Nudi-

branches, 105 Inferobranches, 105, 106: Tectibranches, 106: Hete-

87

ropods, 106 Pectinibranches, 106-108: Tubulibranches, 108:

Scutibranches, 108: Cyclobranches, 108: Acephales testaces, 108—

110: Acephales sans coquilles, 110: Brachiopods, 110, 111.

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99

LETTER VIII.

The locomotion of the Mollusca: connection between the shell and

animal, 113: the muscles, 114.-Swimmers: the Pteropods, 114-118:

the Heteropods, 118, 119: the Cephalopods, 119, 120: the Nautilus,

121-123: the Paper Nautilus, or Argonaut, 123–125: the Salpæ

and Pyrosomæ, 125, 126.-Crawlers: the Cephalopods, 126: the

Gasteropods, 126-132: the Ianthina, 132-134: the Litiopa, 134:

Bivalve Mollusca, 135: Bivalvular Leapers, 136: Bivalvular Swimmers,
137, 138.

112

LETTER IX.

Burrowing and stationary Mollusca: arenacolous, 139–141: byssife-

rous, 141–145: cemented and pedunculated, 145, 146: stationary

Gasteropods, 146, 147: the Patellæ, 147, 148.

139

LETTER X.

Boring Mollusca and nest-builders: saxicavous Mollusca, 149, 150 :

their mode of operation by boring, 151 by a solvent, 151, 152: Mr.

Osler's theory, 152–157 : Mr. Garner's theory, 157: Mr. Hancock's

discoveries and theory, 157-162: saxicavous Gasteropods, 162: snails

are doubtful borers, 162-164: nest-builders and carriers, 164-166:

classification of Mollusca from differences in their power of locomotion,
167. .

149

LETTER XI.

Their system of aqueducts : variation of size in the same individual,

168, 169 how produced, 169-171: description of the aquiferous

system, 171-174.

168

LETTER XII.

Their nervous system and senses: happiness of Mollusca, 175, 176:

instincts, 176-179: nervous system, 180-182: senses, touch, 182

-184: taste, 184: smell, 184-187: sight, 187-196: eyes of the

bivalves, 187 of the Cephalopods, 188: of the Gasteropods, 189-192:

their number and position, 193, 194: not produced by innate desires,

194-196 hearing, 197--200: noises of Mollusca, 200, 201.

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. 175

LETTER XIII.

Their circulating system, 202-204: circulation in the Cephalopods,

204-208 in the Gasteropods, 209-212: in the Conchifera, 212-

214 in the Tunicata, 214-216: more modern views of the circula-

tion in the Mollusca, 216-221: the pulse in Mollusca, 221, 222: the

blood, 223, 224.

. 202

LETTER XIV.

Their secretions: shell, 225-227: pearl, 227-233: colours, 233,

234: mutability of the Cephalopods, 235-238: inky secretions, 238-

241 purples, 241-244: urinary secretions, 244-246: mucus, 246,

247 phosphorescence, 247-251: electricity, 251: heat, 251.

225

LETTER XV.

Their respiration, 252, 253: vibratile cilia, the functions of, 253-

255: effects of respiration, 255–257: can be long suspended, 257:

torpidity, 258-261: hybernation, 261-266: relation between respira-

tion and locomotion, 267: relation of respiration to habitat, 267, 268. 252

LETTER XVI.

Organs of respiration: pulmoniferous Mollusca, 269, 270: branchi-
ferous Mollusca, 270: Mollusca with external branchia, 270-272: with
covered branchiæ, 273: with internal branchiæ, 273, 274: branchiæ