LIST OF ILLUSTRATIONS xiii 
Mouth-Organs of Sheep-Tick, 
PAGE 
. 244 
English Sheep-Tick, 
. 244 
Dog- or Sheep-Tick, 
. 245 
Pigeon-Tick, 
. 245 
Cheese-Mite 
. 245 
Itch-Mite, . 
. 246 
Demodex folliculorum, 
. 246 
A Spider’s Spinnerets, 
. 247 
Slender Sea-Spider, 
. 248 
Shore-Spider, 
249 
Chinese King-Crab, 
. 250 
A Trilobite, 
. 252 
Nauplius Larva of Barnacle, 
. 253 
Zoaea Stage of Crab, 
. 254 
Jaws of Crayfish, . 
. 254 
Young Edible Crab, 
. 256 
Swimming Crab, . 
. 256 
Indian Land-Crab, 
. 257 
Swift Land-Crab, . 
. 258 
Calling-Crab, 
258 
Thornback Crab, . 
. 259 
Long-Beaked Spider-Crab, 
. 261 
Dromia Crab, 
. 261 
Broad-Clawed Porcelain-Crab, 
. 262 
One-Clawed Lobster, 
. 265 
Larva of Crayfish, . 
. 266 
Slender-Clawed Crayfish, . 
. 266 
Common Crayfish, 
. 267 
Common Prawn, . 
. 268 
West Indian Prawn, 
. 269 
Mussel-Prawn and Sponge-Prawn, 
. 270 
Hooded Shrimp, . 
. 270 
Long-Necked Shrimp, 
. 271 
Mantis-Shrimp, 
. 272 
Serolis bromleyana ,. 
. 274 
Sphceroma, . 
. 275 
Male and Female Gnathia, 
. 275 
Common and Pill Wood-Lice, 
. 276 
Fresh-Water Shrimp, 
. 277 
Sand-Hopper, 
. 277 
Spiny Shrimp, 
. 277 
Gigantic Andania, 
. 278 
Skeleton-Shrimp, . 
. 278 
Whale-Louse, 
. 279 
Transparent Ocean-Shrimp, 
. 279 
Phronima, . 
. 280 
Barnacles attached to Pumice, 
. 281 
Acorn-Barnacle, 
. 282 
Stalkless Barnacle, 
. 282 
Parasitic Cirripedes, 
. 282 
Parasitic Barnacles, 
. 282 
Copepods, . 
. 283 
Fish-Lice, . 
. 284 
Spiny-Tailed Water-Flea,. 
. 285 
PAGE 
Egg-Capsule of Water-Flea, . . 285 
Glassy Leptodora, .... 286 
Scale-Tailed Apus, . . . 286 
Branchipus, and Brine Shrimp, . . 287 
Peripatus, ..... 288 
Anchor Sea-Cucumber, . . . 290 
Sea-Cucumbers and Brittle-Star, . .291 
Ambulacral System of Starfish, . . 292 
Group of Stone-Lilies, . . . 294 
Lofoden Root-Crinoid, . . . 297 
Medusa-Head Pentacrinid, . . 299 
Rosy Feather-Star and Sabella, . . 300 
Parasitic Swellings on Crinoids, . . 303 
Blue China Star-Fish, . . . 304 
Pedicellarice, .... 305 
Starfish Turning Over, . . . 306 
Common Brittle-Star, . . . 307 
Edible Sea-Urchin, . . . 308 
Jaws of Stone-Urchin, . . . 309 
Shield-Urchin, .... 309 
Fiddle Heart-Urchin, . . .310 
Phial-Shaped Pourtalesia, . . 311 
Leather-Urchin, . . . .311 
U-Shaped Sea-Cucumber,. . . 312 
A Deep-Sea Holothurian ( Scotoplana ), . 313 
„ „ ( Psychropotes ), . 314 
Club-Like Sea-Cucumber, . 314 
A Plated Holothurian, . . .314 
Green Snake-Star,. . . .315 
Development of a Sea-Urchin (Stages 1 -8), 316 
„ „ (Stage 9), . 316 
„ „ (Stage 10), . 317 
Young Sea-Urchin, . . 318 
Brood-Pouch of Sea-Urchin, . . 319 
Beak of Cuttle-Fish, . . 327 
Common Octopus, .... 329 
Shell of Female Argonaut, 332 
Male Argonaut, .... 333 
Common Squid, .... 335 
Sepiola, ... . 336 
Shell of Spirula, .... 338 
Section of Shell of Pearly Nautilus, . 339 
A Ceratite,..... 340 
An Ammonite, .... 340 
Shell-Bearing Slug ( Testacella ), . • 343 
Glass-Snail and Amber-Snail, . . 344 
Black Slug, . . - .345 
Clausilia, ..... 347 
Agate-Snail ( Achatina ), . ■ • 348 
Pythia scarabceus, .... 349 
Earlet Shell {Auricula), . - • 349 
Embryo of River-Limpet, . . . 350 
Teeth of Snails, .... 350 
Common Pond-Snail {Limncea), . . 351 
