CONTENTS. Vil 



MOLLUSCA, OR SOFT-BODIED ANIMALS. 



FIRST GROUP THOSE DESTITUTE OF A DISTINCT HEAD Actpliala. 



CLASS I. TUNICATA. 



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Meaning of the Term. Paps. Their Structure 1G3 



Parasite Transparency. Beauty of Colouring. Phosphorescence 164 

 Reproduction in the Salpae 165 



CLASS II. BRACHIOPODA, 



Meaning of the Term. Peculiarity of Structure 165 



Depths at which they live 166 



CLASS III. LAMELLIBRANCHIATA. 



Meaning of the Term 166 



Development of Ova Oyster : how supplied with Food 167 



Susceptibility to Light. Growth 168 



Pearls Pearl-divers and Fisheries 169 



Scallop. Mussel and its Byssus. Silk of the Pinna 170 



Foot of the Cockle. Use of the Limpet as Food 171 



Value of Oysters. Mollusca adapted to the character of the Coast 172 



Boring Species Teredo 173 



SECOND GROUP THOSE WITH A DISTINCT HEAD 



CLASS I PTEROPODA. 



Meaning of the Term. Clio borealls : Abundance of 175 



Its multitude of Suckers 176 



CLASS II. GASTEROPODA. 



Meaning of the Term 176 



Variety and Beauty of some Marine Tribes (Nudibranchiata) 177 



The Limpet: its Gills, Food, Tongue Chiton 178 



Sea-hare. PlanorUs ]79 



Sense of feeling in the Slug. Helix: number of Species 180 



Uses as food 181 



Vermetus Habits of the Whelk. Purple dye of the Dog Whelk.. 182 

 Tynan Purple. How procured ,.. 183 



CLASS III. CEPHALOPODACUTTLE-FISH. 



Structure. Pearly Nautilus 184 



Ammonites Common Cuttle-fish Loligopsis 185 



