88 PALAEONTOLOGY OF NEW YORK. 



Crenipecten Leon. 



PLATE IX, FIG. 12; AND PLATE LXXXIII, FIG. 8. 

 Creiiiperten Lam, Hall. Pal. N. Y.. vol. v, pt. 1. Plates and Explanations: PI. 9, fig. 12. Jan., 1SS3. 



Shell of medium size, ovate, slightly oblique; length about one-sixth less than 

 the height ; mat-gins regularly curved, produced below, rather straight on 

 the upper part of the posterior side. 



Left valve moderately convex ; the greatest convexity is a little below the 

 middle. 



Hinge-line straight, short, nearly central; length about one-third the 

 height of the valve. 



Beak acute, erect. Umbonal region not strongly marked, subtending au 

 acute angle. 



Ears sub-equal, small, sulci not conspicuous ; posterior ear the larger. 

 A narrow rim, slightly elevated and free from rays, extends from the poste- 

 rior ear along the margin of the shell. 



Surface marked with numerous distinct, rounded or sub-angular rays, and 

 wider interspaces with smaller intermediate rays ; with fine concentric stria? 

 and undulations at irregular intervals. The rays are stronger over the pos- 

 terior half of the valve. 



Ligamental area linear, and crenulated with narrow cartilage-pits. 



The specimen figured has a length of 26 mm., height 30 mm., hinge-line 

 10 mm. 



This species differs from all the others in its form and surface characters. 

 Formation and locality, in sandstone of the Chemung group at Leon, Catta- 

 raugus county, N. Y. 



