PLATE XLIV 



PAGE 



Figs. 1-3. CORBULA PERCOMPRESSA Gardner n. sp 717 



1. Exterior of right valve. X 3. 



2. Interior of same. X 3. 



3. Dorsal view of double valves. X 3. 



Monmouth formation, Brightseat, Prince George's County. 



Figs. 4-8. CORBULA MONMOUTHENSIS Gardner n. sp 715 



4. Exterior of left valve. X 3. 



5. Interior of same. X 3. 



6. Exterior of right valve. X 3. 



7. Interior of same. X 3. 



8. Dorsal view of double valves. X 3. 



Monmouth formation, Brooks' Estate near Seat Pleasant, 

 Prince George's County. 



Figs. 9-15. CORBULA SUBRADIATA Gardner n. sp 718 



9. Exterior of left valve. X 5. 



10. Interior of same. X 5. 



11. Exterior of right valve. X 5. 



12. Interior of same. X 5. 



Monmouth formation, Brooks' Estate near Seat Pleasant, 

 Prince George's County. 



13. Double valves from left side. X 5. 



14. Same from left side. X 5. 



15. Dorsal view of same. X 5. 



Monmouth formation, Brightseat, Prince George's County. 



940 



