753 



Peod. 



all others by its regular wiie form and equal convexity, as well 

 as by its distantly disposed and very slender spines, by the 

 peculiar punctate structure of the exfoliated shell, and the 

 striato-punctate surface of the cast. The form and character 

 of well-preserved specimens are shown in figs. 36, 37, and 38, 

 which give the outline, cardinal and profile views of a ventral 

 valve. Figs. 39 and 40 are hinge views of ventral casts, with 

 muscular impressions, and one of them showing cavities on 

 each side of the beak made by the dental lamellae. Figs. 30, 

 31 are dorsal interiors ; 32, a hinge view. — In the sandy and 

 limey Chemung heds at Conewango, Napoli, and New Albion, 

 Cattaraugus Co., N. Y. — YIII g, 



Productella pertenuis. {Productus pertenuis. Meek 

 Pal. East Nebraska, 1872, Coal measures.) — In Pennsylvania 

 identified by C. E. Hall in Spec. C 1-6 (000, p. 253) of Con- 

 gruity, Westmoreland, from Barren measures. XIV, 



Productella rarispina, {Productus rarispinus. Hall, 



:£>. 



Nat/, FaL/VX Vo/JV. fUfe Xxrv. 



10th Regents Rt. 1857. Chemung,) Hall, Pal.N. Y. Vol. IV, 

 1867, page 170, plate 24, figs. 1 to 9. It occurs in the same beds 

 with P. loydii and P. hirsuta^ but is easily distinguished from 

 them by its greater gibbosity and fewer spines; and its casts, 

 by extremely fine papillas and their extension in hairlike striae. 

 In general characters it resembles P. suhalataoH the Hamilton 

 formation^ in Illinois. Found in the ChemunghedsdX Phillips- 

 burg, Alleghany Co., N. V., and on Tioga river. — In Pennsyl- 



