I 



49 2 MOLLUSKS: ACEPHALS. 



Fig- 455- Fig. 456. 



Ca rdicum islandicum, Linn. 



One half. New England. Unig comflanatuSj Lea . New Eng i and and westward. 



Fig. 458. 



Fig. 459. 



Unioflexuosiis, Raf. Two thirds. Western States. 

 Fig. 460. 



Unio sfinosa, Lea. One half. 

 Georgia. 



Unio clava, Lam. Two thirds. Western States. 



