PLATE XLII 



PAGE 



Fig. 1. CYPRIMERIA MAJOR Gardner n. sp 689 



Exterior of gerontic right valve. Monmouth formation, Brightseat, 

 Prince George's County; U. S. National Museum. 



Fig. 2. TELLINA (ACROPAGIA) GABBI Gardner n. sp 694 



Exterior of right valve. Monmouth formation, 1 mile west of Friendly, 

 Prince George's County. 



Figs. 3, 4. AENONA EUFALENSIS Conrad 697 



3. Exterior of left valve. X 2. Monmouth formation, Brightseat, 



Prince George's County. 



4. Exterior of right valve. X 2. Monmouth formation, near Oakland, 



Prince George's County, U. S. National Museum. 



Figs. 5, 6. TELLINIMERA EBOREA Conrad 695 



5. Exterior of right valve. X 2. 



6. Dorsal view of double valves. X 2. 



Monmouth formation, Brooks' Estate near Seat Pleasant, 

 Prince George's County. 



Figs. 7, 8. LEPTOSOLEN BIPLICATA Conrad 703 



7. Dorsal view of internal cast of double valves-. Monmouth formation, 



2 miles southwest of Oxon Hill, Prince George's County. 



8. Exterior of right valve. X 2. Monmouth formation, Brightseat, 



Prince George's County. 



938 



