







L 





KEY TO THE FAMILIES. 



(ADAPTED TO THE NEW ZEALAND GENERA.) 



Class Cephalopoda. 



Arms forming a circle round the head. 

 (a.) Arms eight. 



. Naked; arms similar 

 ARGONAUTID.E. In a shell, one pair of arms webbed at the extremity 



Arms ten. 



ONTCHOTEUTHID^;. Eyes naked, interior shell horny 

 LouGiD.ffi. Eyes covered with skin, interior shell horny 

 SEPIADJE. Interior shell calcareous 

 SPIRULID.E. Interior shell spiral 



(c.) Arms numerous. 



. With an external spiral shell 



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2 

 3 

 4 

 4 



Class Pteropoda. 



Fins on the side of the mouth or head. 



HYALID^;. Covered with a thin horny shell 

 DENTALIID.E. Shell tubular 



5 

 5 



Class Heteropoda. 



Foot formed into a raft. 



IANTHIN^E. Enclosed in a spiral shell 

 . Shell limpet-shaped 



6 

 6 



Class Gasteropoda. 



Shell univalve, multivalve, or none. 

 1. Shell regularly spiral. 



(.) Shell fusiform, tapering to eacli end. 



MUEICID^;. Anterior canal straight ; aperture entire behind ... 7 

 TBITONID.E.: Large, canal short, with few varices ... ... 12 



:. Shell notched in front ... ... ... ... 14 



E. Columella flattened, last whorl large ... ... 16 



(part). Columella curved to the right ... ... 14 



CANCELLARIDJE. Columella plicated ... 



TRICHOTOPID^E. Shell thin, keeled ... ... ... ... 26 



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