PLATE XLI 



PAGE 



Figs. 1-4. CYPKIMERIA MAJOR Gardner n. sp 689 



1. Exterior of left valve of young specimen. 



2. Interior of same. 



3. Exterior of left valve of adult specimen. 



4. Interior of same. 



Monmouth formation, Brightseat, Prince George's County. 



Figs. 5, 6. CYCLINA PAKVA Gardner n. sp 678 



5. Interior of right valve. X 6. 



6. Exterior of same. X 6. 



Monmouth formation, Brightseat, Prince George's County. 



937 



