5S0 INDEX. 



Entomoatraca — continued. f-^c^ 



Salt-water slirimps .,....<, 226 



Seventh Order of Crustaceans : — 



Sword-tails . . . . . . . .226 



Kino:-crabs ........ 226 



Eighth Order : — 



Sucking-mouthed crustaceans ..... 227 



Pyenogons. ........ 228 



Fish-lice 228 



Lerueans ......... 228 



Ninth Order of Crustaceans : — 



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



Skeleton wheel-bearer 230 



Ciliary movement ....... 231 



Eggs of rotifera • . . . . . . .282 



Tenth 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 



Heterooranccliata ....... 239 



CHAPTER XIV. 



Fu'st Class of Mollusca : — 



Polyzoa 243 



Sea-mats ......... 243 



Sea-moss ......... 245 



Avicularia. ........ 246 



Fluviatile Polyzoa 248 



CHAPTER XV. 



Second Class of Mollusca :-- 



Tunicata 249 



Ascidians ......... 251 



Beauty and delicacy of their internal strustiir . . 251 



Salpians ......... 251 



Pyrosoma, its dazzling splendour .... 253 



Compound Ascidians ....... 253 



CHAPTER XVI. 



Third Class of Mollusca : — 



Conchifera .... 



Scallop, its structure . 

 Its mantle, gills, mouth, and hinge 

 Elaborate mechanism of the gill-fringe 

 Classification of conchifera . 



254 



255 

 256 

 258 

 259 



