PLATE 5. 



Paga. 



Fig-. 1. Paeapholas sphenoideus 300 



a. Lateral view ; right side. 

 6. Dorsal view. 



c. Veutral view. 



d. Front view. All of the same example,, and all enlarged two 



diameters. 



Fig-. 2. Tancredia ? ccelionotus 288 



a. Eight-side view ; natural size. 

 i. Dorsal view of the same example. 



c. Front view of the same. 



d. Eight-side view of the cast of anotlier example ; showing pallial 



sinus and posterior abductor scar. 



Fig. 3. Orassatella oiimarrointensis 287 



a. Left-side view ; natural size. 



b. Dorsal view of the same. 



c. Front view of the same. 



Fig, 4. Cardium trite 292 



a. Natural cast of right valve ; natural size. 



h. Gutta-percha cast of a portion of a natural mould of the exte- 

 rior surface ; enlarged three diameters ; showing spines on every 

 third rib. 



Fig. 5. Pachyiiya ? herseyi 298 



a. Left-side view ; natural size. 



h. Dorsal view of the same example. 



Fig. 6. OsTREA quadriplicata , 275 



a. Lower valve, natural size ; the marginal processes in this exam- 

 ple are somewhat longer than usual. 

 See, also, Plate 8, figs. 3 a and h. 



Fig. 7. Pachyitya austinensis 298 



a. Side view of a young example from Salado, Tex ; natural size. 

 6. Front view of the same. 



See, also, Plate 8, figs. 1 a and b. 



