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THE NAUTILUS. 



gracilis Bar. 



leptodon Raf. 

 Obovaria 



leibii Lea. 



ellipsis Lea. 

 Plagiola 



elegarts Lea. 



donaciformis Lea. 

 Obliquaria reflexa Raf. 

 Strophitus edentulus Say. 



marginata Say. 

 imbecilis Say. 

 grandis footiana Lea. 



grandis benedictensis Lea. 

 Anodontoides ferussaciana sub- 



cylindracea Lea. 

 Symphynota 



compressa Lea. 



costata Raf. 

 Alasmidonta 



marginata varicosa Lam. 

 calceolus Lea. 

 Hemilastena ambigua Say. 



t/mo gibbosus Bar. 

 Quadrula 



hippopcea Lea (plicata Say ?). 



lachrymosa Lea. 



pustulosa Lea. 



rnbiginosa Lea. 



undata Bar. (?). 



coccinea paupercula Simp. 



subrotunda Lea. 



tuberculata Raf. 



Strophitus undulatus Say,, 

 Anodonta 



marginata Say. 



cataracta Say. 

 implicata Say. 



Alasmidonta 

 undulata Say. 

 marginata varicosa Lam. 

 heterodon Lea. 



Margaritana margaritifera L. 

 complanatus Dill. 



The Atlantic fauna is made up of five genera and thirteen species, 



