Klymklla lkvata. a .xiieciineii i-etaiiiing- lioth valves in conjunc- 

 tion. SvK pa^ 504. Hamilton Gi-ouj). Schoharie County, N. Y. 



Pahbrka altkbnata. View of a large right valve showing the form of the shell and the general charac- 

 ter of the 8Ui-face ornamentation. The central portion of the valve has l)een broken away, and the ra<lii are 

 obscure on the marginal jxirtions. 'I'he specimen is pi-esci-ved in the rtolomitic limestone of the Upper 

 Uelderberg group, from near Columbus, Ohio. See pag'e 416. 



