49 2 MOLLUSKS I ACEPHALS. 



Fig. 455- Fig. 456. 



Ca.rd.icum islandicum, Linn. 



One half. New England. UM* *&****, VUL New England and westward. 



Fig. 458. 



Fig. 459- 



Unioflexttosus, Raf. Two thirds. Western States. 

 Fig. 460. 



L nio spinosa, Lea. One half. Unio clava, Lam. Two thirds. Western 



Georgia. 



