PLATE XXXII 



PAGE 



Figs. 1-3. GRYPH^EA (PYCNODONTE) VESICULARIS (Lamarck) Race D 576 



1. Interior of left valve of adult. 



2. Exterior of left valve of younger individual. 



3. Double valves of same viewed from right side. 



Monmouth formation, Brightseat, Prince George's County. 



928 



