49 2 



MOLLUSKS: ACEPHALS. 



455- Fig. 456. 



Cardicum islandicum, Linn. 



One half. New England. Unio com ^ anatus ^^ New England and westward . 



Fig. 458. 



Fig. 459- 



Unioflexuosus, Raf. Two thirds. Western States. 

 Fig. 460. 



Unio spinosa, Lea. One half. 

 Georgia. 



Unio clava, Lam. Two thirds. Western States. 



