VI CONTENTS. 



CHAPTER IV. p^gj, 



Structitre and Physiology of the Mollusca. — Nervous 

 system; organs of sense. — Muscular system. — Digestive 

 system ; lingual teeth ; secretions. — Circulating system ; 

 aquiferous canals. — Respiratory system. — The shell, its 

 composition and structure; nacreous, fibrous, and porcel- 

 laneous shells ; epidermis ; erosion of fresh-water shells. 

 Formation and growth of the shell ; adult characters ; de- 

 collated shells ; monstrosities ; colours ; the operculum ; 

 homologies. — Temperature and hybernation. — Reproduc- 

 tion : of lost parts ; by gemmation ; viviparous ; alternate ; 

 oviparous. — Development 21 



CHAPTER V. 



Classification. — Affinities ; analogies ; species ; genera ; fami- 

 lies ; the quinary system 55 



CHAPTER YI. 

 NoMENCLATUEE. — Synouyms ; authorities; types 59 



Abbreviations 61 



SYNOPSIS OF THE GENERA. 



Class I. Cephalopoda. Order I. Dibranchiata 62 



Section A. Octopoda 64 



Fam. I. Argonautidce. — Argonauta 66 



Fam. II. OctopocUda. — Octopus, Pinnoctopus, Eledone, 



Cirroteuthis, Philonexis 67 



Section B. Decapoda 6S 



Fam. III. TeidhidcB. — Loligo, Gonatus, Sepioteuthis, Belo- 

 teuthis, Geoteuthis, Leptoteuthis, Cranchia, Sepiola, Lo- 

 ligopsis, Cheiroteuthis, Onychoteuthis, Enoploteuthis, 

 Ommastrephes 69 



