4bl 



PLATE LXXII. 



Paracyclas Ohioensis. 



P)i^ 442. 



See Plate 95. 

 Fig. 1. The right side of a specimen retaining' the test. 



Hamilton group. Falls of the Ohio river. 



PaRACTCLAS lilRATA. 



Page 441 

 See Plate 95. 

 Figs. 2-5. A Herie.s of specimens illustrating the principal varieties of form and surface markings charac- 

 teristic of the species, as found in the Cherty beds, above the Corniferous limestone belonging 

 to the Hamilton group, at the falls of the Ohio river and in Clarke Co., Ind. 

 Figs. 6-19. A series illustrating the i)rincipal varieties as found in th(! Hamilton group in the State of New 

 York. Figs. 9, 10 and 13 illustrate specimens distorted by pi-essure. 



Paracyclas tenuis. 



Page 443. 

 See Plate 95. j 



Figs. 20, 21. Two right valves enlarge<l to three diameters. J 



Hamilton group. Belhma and shore of Cayuga lake, N. ¥. ' 



Fig. 22. A large left valve enlarged to three diameters. 



Hamilton gi-oup. Shore of Skaneatelet lake, N. Y. 



T/? -.^nwoils te 



