PALAEONTOLOGY OF NEW YORK. 
Crenipecten Leon. 
PLATE IX, PIG. 12; and PLATE LXXXIII, FIG. 8. 
Crenipecten Leon, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PL 9, tig. 12. Jan., 1883. 
Shell of medium size, ovate, slightly oblique ; length about one-sixth less than 
the height; margins 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 an 
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 striae 
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. 
