358 PALEONTOLOGY OF NEW YORK. 



the shell. Some portions of the shell preserved along the cardinal line give 

 indications of one or more lateral folds or teeth. 



The specimen described has a length of 35 mm. and a height of 20 mm. 



This species differs from all the others here described in its regular elliptical 

 form. Although its identity with Nyassa is not fully established, there seems 

 no sufficient reason to doubt its relations to this genus. 



Formation and locality. In the Corniferous limestone, at Stafford, Genesee 

 county, N. Y. 



GRAMMYSIA, De Verneuil. 1847. 



a. cingulata. 



Grammysia ovata, n. sp. 



PLATE XCIII, FIG. 22. 



Shell of medium size, ovate ; length about one-third greater than the height ; 

 basal margin broadly curving with a slight constriction near the middle. 

 Posterior extremity abruptly recurved from the base and obliquely sub- 

 truncate above. Cardinal line nearly straight, slightly declining posteriorly. 

 Anterior end short, regularly rounded below the lunule. 



Valves regularly convex in the lower and posterior portions, gibbous in 

 the middle and above. 



Beaks sub-anterior, moderately prominent. Cincture shallow, distinctly 

 defined above, extending from the beak obliquely to the basal margin, at 

 about the middle of its length. Umbonal slope sub-angular, continuing to 

 the post-inferior extremity. 



Surface marked by fine concentric striae, which on the anterior and umbonal 

 portions are fasciculate, rising into sub-angular folds or ridges. Interior 

 unknown. 



The specimen described has a length of 60 mm. and a height of 38 mm. 



This species bears some resemblance to G. bisulcata, but is a proportionally 

 longer shell, the cincture is shallower, and there are no accompanying folds or 



