PLATE LXVI 



PAGE 



Figs. 1-5. CYPRICABDELLA TENUISTRIATA (Hall) 656 



1. Cast of interior of left valve. Sideling Hill Creek, 2y 2 miles above 



mouth, 1700. 



2. Right valve. Two miles north of mouth of Town Creek, 1716. 



3. Right valve, somewhat questionably referred to this species, upon 



which concentric striae of umbo are nearly obsolete. Two miles 

 north of mouth of Town Creek, 1632. 

 Jennings formation, Parkhead member. 



4. Large left valve. Hamilton formation, New York. 



Figs. 6-12. CYPRICARDELLA NITIDULA n. sp 656 



6. Left valve showing the well marked umbonal slope and strong 



concentric ridges. X 2. 



7. Internal cast of left valve showing muscle scars and hinge. X 2. 



8. Gutta-percha squeeze of hinge of left valve. X 2. 



9, 10. Two left valves of an elongate finely lined shell, with posterior 

 umbonal ridge close upon the margin. These shells resemble in 

 outline C. tenuistriata Hall except for the position of the pos- 

 terior ridge. 



11. Gutta-percha squeeze showing interior of right valve. X 2. 



12. The interior of a small left valve of the same species. 



Jennings formation, Chemung member, figs. 6-11 Deer Park, 

 fig. 12 National Road, west of Frostburg. 



Fig. 13. CYPRICARDELLA CUMBERLAND!^ n. sp 657 



Cast of interior left valve. Jennings formation, Chemung member, 

 Allegany Grove. 



Figs. 14-20. CYPRICARDELLA CRASSA n. sp 657 



14, 15. Left valves. 



16. Cast of interior of right valve. 



17. Cast of interior of left valve. 



18. Right valve. 



19. Interior of right valve. 



20. Hinge of right valve enlarged X 2. 



Jennings formation, Chemung member, National Road, east of 

 Millstone, 2761. 



Fig. 21. CYPRICARDINIA ELEGANS n. sp 659 



Left valve of type. Jennings formation, Chemung member, National 

 Road, 300 feet west of schoolhouse, Belle Grove. 



Figs. 22-24. CYPRICARDINIA ELEGANS VAR. ANGUSTA n. var 659 



22. Cast of interior of left valve. 



23. Dorsal view of internal cast. The valves are not equal in convexity 



as the figure seems to indicate. 



24. Right valve. 



Jennings formation, Chemung member, Town Creek, 3584. 



Fig. 25. PARACYCLAS MARYLANDICA n. sp 660 



Right valve of type. Jennings formation, Chemung member, Town 

 Creek, 3870. 



149 



