CONTENTS, 



Primary Divisions of the Animal Kingdom, 



Classes of the Malacozoa, 



Anatomy of the Mollusca : — 





External Features, . . • . . 



8 



The Skin, 



. 11 



The Shell, . 



14,53 



The Operculum, 



. 41 



Cartilages, 



. 60 



Muscles, Arms and Fins in the Cephalopoda, 



. 62 



Organs op Movement in the Gastropoda, etc.. 



. 65 



Organs of Movement in the Pelecypoda, . 



. 67 



Nervous System, ... . . 



. to 



Organs of Sense, . . ... 



. 75 



Respiration, 



. 81 



Circulation, Aquiferous System, 



. 88 



Digestive Organs, . . . 



. 91 



Organs op Secretion, 



. 106 



Sexual Organs, 



. 110 



Development, 



. 125 



Reproduction of Destroyed Organs, . 



. 133 



Habits and Economy op the Mollusca, 



. 134 



(Tii) 



