PLATE LXIII 



PAGE 



Fig. 1. LIOPTERIA AURICULATA n. sp 636 



Exterior of left valve. The anterior ear is made too large in drawing. 

 Jennings formation, Woodmont member, Ithaca fauna, National 

 Road, east of Millstone, 795. 



Fig. 2. LIOPTEBIA sp. 



A small suberect left valve with short posterior wing and concen- 

 trically lined surface. Jennings formation, Chemung member, 

 Trout River, 2 miles south of Oakland. 



Fig. 3. LEPTODESMA ROGERSI Hall 636 



Right and left valves. Ithaca beds, Norwich, N. Y. 



Figs. 4-8. LEPTODESMA LONGISPINUM Hall 637 



4. Right valve. Chemung formation, New York. 



5. Left valve with posterior spine restored. Near Oakland. 



6. Left valve doubtfully referred to this species. National Road, 6 



miles west of Frostburg. 



7. 8. Right and left valves. Same locality. 



Jennings formation, Chemung member. 



Figs. 9, 10. LEPTODESMA AGASSIZI Hall 637 



9. Left valve. 



10. Right valve. 



Chemung formation, New York. 



Figs. 11-15. LEPTODESMA MEDON Hall 638 



11. Small left valve. National Road, 7 miles west of Frostburg. 

 12, 13. Right valves. Allegany Grove, 2307. 



14, 15. Left valves. Allegany Grove, about 2215. 

 Jennings formation, Chemung member. 



Figs. 16, 17. LEPTODESMA NAVIFORME Hall 639 



16. Exterior of large right valve showing faint radiating striae. 



17. Exterior of right valve of somewhat different proportions. 



Jennings formation, near base of Parkhead member, Williams 

 Road, 4 miles east of Cumberland. 



Figs. 18, 19. LEPTODESMA LICHAS Hall 640 



18. Left valve. Jennings formation, Chemung member, National Road, 



6 miles west of Frostburg. 



19. Left valve. Chemung formation, New York. 



Fig. 20. LEPTODESMA ELONGATUM n. sp 640 



Left valve. Jennings formation, near top of Chemung member, Keyser- 

 Piedmont Road, 2% miles west of Keyser, W. Va. 



Fig. 21. GOSSELLETIA sp 641 



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

 Williams Road, Polish Mountain. 



146 



