LIST OF ILLUSTRATIONS xxi 



FIG. PAGE 



144. Carpet beetle, larva, and pupa 245 



145. Culex and larva 246 



146. Internal organs of cockroach ...... 247 



147. Periplaneta, its tracheal system 248 



148. Periplaneta, nervous system 249 



149. Honey bee, queen, worker, and drone .... 253 



150. Red ant, male, worker, and female 253 



151. Euscorpio 255 



152. Scorpion, ventral side 256 



153. Scorpion, internal organs 258 



154. Epeira diadema 259 



155. Cattle tick 260 



156. Itch mite 260 



157. Limulus, ventral view 261 



158. Anodonta cygnea, entire animal 265 



159. Anodonta cygnea, right valve, and animal .... 268 



1 60. Anodonta, section of shell and mantle .... 269 



161. Anodonta cygnea, animal 270 



162. Anodonta cygnea, dissection from left side . . . . 273 



163. Anodonta cygnea, sections of gills . ... . 274 



164. Anodonta, diagram of circulatory system .... 276 



165. Anodonta, embryo and glochidium . . ... 278 



1 66. Mytilus edulis 279 



167. Teredo navalis . . . ... ... . . 280 



1 68. Chiton spinosus . . 281 



169. Chiton, ventral view 282 



170. Chiton, nephridial and genital systems .... 283 



171. Helix nemoralis 285 



172. Triton nodiferus, shell 286 



173. Triton nodiferus, median section of shell . . . . 287 



174. Solarium perspectivum, under side . . .- . . 288 



175. Terebra oculata, shell 289 



176. Cyprsea moneta, animal expanded, in its shell . .... 290 



177. Doris tuberculata 290 



178. Shell-bearing Pteropoda . 291 



179. Patella vulgata, animal, ventral view 292 



1 80. Limax, lung-cavity, etc 293 



181. Triton nodiferus 294 



