PLATE XXXIV 



PAGE 



Figs. 1, 2. TRIGONIA EUFALENSIS Gabb 582 



1. Exterior of right valve. X 2. 



2. Interior of same. X 2. 



Monmouth formation, Brightseat, Prince George's County. 



Figs. 3-5. PECTEN ARGILLENSIS Conrad 588 



3. Exterior of immature left valve. X 2. 



4. Exterior of adult left valve. 



5. Portion of sculpture of same. X 5. 



Monmouth formation, Brightseat, Prince George's County. 



Figs. 6, 7. PECTEN- VENUSTUS Morton 591 



6. Exterior of right valve. X 3. 



7. Exterior of left valve. X 3. 



Houston, Mississippi, U. S. National Museum. 



Figs. 8, 9. PECTEN SIMPLICIUS Conrad 595 



8. Exterior of left valve. X 2. 



9. Exterior of right valve. X 2. 



Monmouth formation, Brightseat, Prince George's County. 



Fig. 10. PECTEN QUINQUECOSTATA Sowerby 596 



Cast of interior of right valve. Matawan formation, Camp Fox, Chesa- 

 peake and Delaware Canal, Delaware. 



Fig. 11. LIMA OBLIQUA Gardner n. sp 603 



Exterior of left valve. X 3. Monmouth formation, Brooks' Estate near 

 Seat Pleasant, Prince George's County. 



Figs. 12, 13. LIMA RETICULATA Forbes 600 



12. Exterior of right valve. X 5. 



13. Interior of same. X 5. 



Monmouth formation, Brightseat, Prince George's County. 



Figs. 14, 15. LIMA SERRATA Gardner n. sp 602 



14. Interior of left valve. X 4. 



15. Exterior of same. X 4. 



Monmouth formation, 1 mile west of Friendly, Prince George's 

 County. 



