PLATE 14. 
Page 
Fig. 1. Strophodonta ampla. 98 
1 a. A dorsal view of a young individual. 
1 b. An impression of a dorsal valve of a specimen of medium size, showing the cavity left by 
the cardinal process. 
1 c. A ventral valve of a larger individual. 
1 d. A profile of the specimen fig. 1 c. 
1 e. A dorsal view of a large individual. 
1 /. An enlargement of the surface, showing the transverse striae and the elongate, pustulose 
elevations upon their surface. 
1 g. The cardinal area of the ventral valve with a narrow, linear callosity closing the deltidium, and 
a smooth triangular area which is continuous with the other portions of the same surface, 
and "has apparently never been a foramen. 
1 h. The interior of a ventral valve, showing the strong flabelliform muscular scar. The margin 
of the area is broken (a usual condition) by the removal or the separation of the dorsal 
valve. 
1 i. A cast of the ventral valve from the Schoharie grit, showing the muscular scar and the 
strongly punctate surface. 
Fig. 2. Strophodonta concava.. 96 
2 a. Yiew of a ventral valve which is constricted just below the cardinal extremities. 
2 b. A profile of the same. 
2 c. The interior of a dorsal valve, showing the muscular impressions and cardinal process. 
2d. A cardinal view of a cast of the ventral valve, showing the muscular impressions. 
