332 PALEONTOLOGY OF NEW YORK. 



Surface marked by fine, sharp, regular, concentric striae. 



The specimen described has a length of 6.5 mm. and a height of 4.5 mm. 



A single specimen only has been observed. It possesses the general form 

 and surface characters of Leda with some indications of its relations with 

 PAL.EONEILO in its depressed post-basal margin. 



Formation and locality. In the arenaceous shales of the Hamilton group, at 

 Fultonhara, Schoharie county, N. Y. 



Leda pandoriformis. 



PLATE XLVII, FIGS. 49, 50. 



Leda pandnrifonnis, Stkvens. Am. Jour. Sci., 2d ser., vol. 25, p. 262. ISSS. 



Leda {Nuculana) Oh'weiisis, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 47, figs. 40, ."jO. 



1883. 



Shell large, elongate-ovate, sub-cuneate; length more than twice the height; 

 basal margin regularly curving in the middle and posteriorly, more abruptly 

 toward the anterior end. Posterior extremity attenuate, abruptly rounded 

 or sub-truncate. Cardinal line oblique, declining from the beak, and slightly 

 curving upward. Anterior end, in the cast, obliquely sub-truncate above, 

 and regularly rounded below. 



Valves moderately convex, scarcely gibbous in the umbonal region, de- 

 pressed-convex or somewhat flattened along the posterior half. 



Beaks at about the anterior third, rising above the hinge-line. Umbonal 

 ridge obtusely angular, extending to the posterior extremity. 



Surface characters unknown. 



Hinge marked both anteriorly and posteriorly by a row of slender teeth, 

 with a sub-rostral ligamental pit, which is imperfectly represented in the figure. 



The specimen described has a length of 26 mm. and a height of 12 mm. 



This species is larger than any other form here described, with a broader 

 posterior end. It has somewhat the shape of L. diversa, but is less gibbous in 

 the anterior portion and less abruptly attenuate behind. 



Formation and locality. In the Waverly sandstone of Newark, 0., and at Bat- 

 tle Creek, Mich. 



