PLATE LIV. 



PAGE 



Figs. 1-4. Mya arexaria (Linne) 194 



1. Interior of left valve of small individual. Wailes Bluff. X % 



2. Exterior of same. 



3. Interior of left valve of larger individual. Wailes Bluff. X % 



4. Exterior of right valve of same. X % 



