580 INDEX. 



Entomostraca continued. PAGE 



Salt-water shrimps . . . . , . . 226 



Seventh Order of Crustaceans : 



Sword-tails 226 



King-crabs . .220 



Eighth Order : 



Sucking-mouthed crustaceans ..... 227 



Pycnogons. ........ 228 



Fish-lice 228 



Lerneans 228 



Ninth Order of Crustaceans : 



Wheel-bearers, rotifera ...... 229 



Skeleton wheel-bearer ...... 230 



Ciliary movement . . . . . . 231 



Eggs of rotifera . 232 



Tentli Order of Crustaceans 234 



Cirripedia (barnacles) remarkably constructed limbs . 235 



Their casting-net 235 



Divided into two families 237 



Barnacles . . . 237 



Acorn- shells 238 



Mollusca " shell-fish " 239 



Definition of mollusks 239 



Heterogangliata 239 



CHAPTEE XIV. 



First Class of Mollusca : 



Polyzoa ' 243 



Sea-mats 243 



Sea-moss 245 



Avicularia. . . 24f> 



Fluviatile Polyzoa 248 



CHAPTEK XV. 



Second Class of Mollusca : 



Tunicata 249 



Ascidians 251 



Beauty and delicacy of their internal structur . . 251 



Salpians 251 



Pyrosoma, its dazzling splendour .... 253 



Compound Ascidians 253 



CHAPTER XVI. 



Third Class of Mollusca : 



Conchifera .254 



Scallop, its structure . . 255 



Its mantle, gills, mouth, and hinge . . . 256 



Elaborate mechanism of the gill-fringe . . . 258 



Classification of conchifera . . 259 



