PLATE LXI. 



(il{AMMV.SIA AKCUATA. 



Page 373. 

 See Plates 63, 93. 

 Fig«. 1-5. A series of valves pi-esenting the usual chai-actei-s of the species. 

 Pigs. 6, 7. Left side and anterioi- views of a specimen vrhich is vertically compressed. 

 Fig. 8. The right valve of a large indivi<lual. 



Hamilton group. iSchottarie Co., N. Y. 

 Fig. 9. Ciinlinal view of a specimen vertically compressed, giving an extreme angularity to the uinlional 

 slope. 



Hamilton group. •S'Aore of Canaiulaigua lake, N. Y. 



f <ft 



Gkammysia subarcuata. 



rage 375. 

 See Plate 93. 



Figs. 10-12. A series of left valves of the visual character. 



Figa. 13-15. Larger individuals of the same species. 



Figs. 16, 17. The left side and cardinal view of a compi-essed specimen. 



Chemung group. Niar Elmira, N. Y. 

 Fig. 18. A cardinal view of a compres-sed specimen. 



Lower Chemung gi-oup. Ithaca, N. Y. 

 Fig. 19. A caiilinal view of a crushed specimen. 



Lower Chenuuig group. Ithaca, N. Y. 

 Fig. 20. A cardinal view of a crushed specimen. 

 Kg. 21. The right side of a verticjilly compressed specimen. 



Chemung gi-oiip. Near Blinira, N. Y. 

 Fig. 22. An enlargement of the sui-face striae on the i^oat-cai-diiial slope of the siiecimen tig. 19. 



Grammysia undata. 



Pago if7». 

 See Plates 64, 93. 

 Fig. 23. A small left valve. 



Chemung gi-oiip. Near Pananta, N. Y. 



