4 
III. Systematic Index = 2231: — 
Gastropoda 
Amphineura ... 
Aplacopliora 
Polyplacophora 
Prosobranchia 
Opisthobranchia including Pteropoda and Heteropoda 
Pulmonata ... ... 
Scaphopoda ... 
Pelecypoda or Lamellibranchia 
Cephalopoda ... 
PAGE 
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. 70 
. 71 
. 80 
. 80 
. 80 
