PLATE 5 



Pago. 



Fig-. 1. Parapholas sphenoldeus - 300 



a. Lateral view ; right side. 



b. Dorsal view. 



c. Ventral view. 



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



diameters. 



Fig. 2. Tancredia ? cgelionotus 288 



a. Right-side view ; natural size. 

 6. Dorsal view of the same example. 



c. Front view of the same. 



d. Right-side view of the cast of another example ; showing pallial 



sinus and posterior abductor scar. 



Fig. 3. Crassatella cimarronensts. '. 287 



a. Left-side view ; natural size. 



b. Dorsal view of the same. 



c. Front view of the same. 



Fig. 4. Oarditjim trite 292 



a. Natural cast of right valve ; natural size. 



b. 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. Pachtmta % herseyi 298 



a. Left-side view ; natural size. 



b. Dorsal view of the same example. 



FlG. 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 b. 



Fig. 7. Pachyjiya austinensis 298 



a. Side view of a young example from Salado, Tex ; natural si^e. 

 6. Front view of the same. 



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



