PLATE 8. 



Page. 



Fig. 1. Pachymya austinbnsis 298 



a. Left valve, reduced to two-thirds of the natural diameter, from 



Dr. Shumard's figure. 

 &. Natural cast ; dorsal view ; reduced one-half of the natural 



diameter from a specimen from Salado, Tex. 

 See, also, Plate 5, figs. 7 a and b. 



Fig. 2. Ostkea (Alecteyonia) bellaplicata 276 



a. Exterior view of up]Der valve ; natural size. 



b. Interior view of the same. From photograph copies of Dr. 



Shumard's original figures. 

 See, also, Plate 4, figs. 3 a and i. 



Fig. 3. OSTREA QUADEIPLICATA 276 



a. Lower valve; natural size. 



I. Upper valve. Both from photograph copies of Dr. Shumard's 

 original drawings. 

 See, also, Plate 5, fig. 6 a. 



