P1L.ATE XX. 



Page. 



MODIOMORPHA AMBIGUA 239 



Fig. 1. Left valve of a slightly-crushed specimen. 



MODIOMORPHA * PINTOENSIS 240 



Fig. 2. View of the specimen used in the description. 



MODIOMORPHA? DESIDERATA 240 



Fig. 3. Anterior portions of the right and left valves, as they appear on a fragment of lime- 

 stone. 



GRAMMYSIA HANNIBALENSIS 244 



Fig. 4. View of a right valve which is a little compressed. 



GRAMMYSIA ARCUATA 24& 



Fig. 5. Right valve found in the same beds -with the preceding species. 



SANGUINOLITKS AEOLUS 247 



Fig. 6. Elongate form of right valve, very closely allied to the type examples of the species. 

 7, 9. Right and left valves of two sheila that vary in form from fig. 6. 



SCHIZODUS CUNEATUS 232 



Fig. 8. View of the right valve. 



SANGUINOLITES RETUSUS 247 



Fig. 10. Right valve. The radiating ridges of the umbonal slope are too strong in the figure. 



SANGUINOLITES SIMPLEX 24S 



Fig. 11. View of the right valve. 



SANGUINOLITES SALTERI 24S 



Fig. 12. Right valve showing the strong radiating lines of the umbonal slope. 



PINNA CONSIMILIS 236 



Fig. 13. View of a small specimen of the left valve, with portions restored in outline. 



VUCULA INSULARIS 241 



Fig. 14. Left valve, showing general form and the tine, concentric surface strite. 



