328 
PALAEONTOLOGY OF NEW YORK. 
Nuculites Nyssa. 
PLATE XLVII, FIGS. 20, 30. 
Nuculites Nyssa, Hall. Prelim. Notice Lamellibranchiata, 2, p. 5. 1870. 
In part “ “ “ Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 47, tigs. 25-30. 1883. 
Shell of medium size, broadly ovate, wider anteriorly; length about one-tliird 
greater than the height; basal margin regularly curving, abruptly rounding 
into both extremities; posterior margin oblique, sub-truncate above and 
abruptly rounded below. Cardinal line short, slightly arcuate. Anterior end 
short, rounded. 
Yalves highly convex, gibbous in the umbonal region. 
Beaks at about the anterior fourth, incurved, rising a little above the hinge. 
Umbonal ridge prominent, extending to the post-inferior extremity. Cardinal 
slope abrupt. 
Surface marked by tine concentric striae, which are slightly fasciculate, 
producing low undulations of the surface. 
Muscular scars faintly impressed. Clavicular ridge narrow, curving toward 
the anterior end and extending about two-thirds the height of the valve. 
The two specimens described measure respectively 18 and 14 mm. in 
length and 12 and 10 mm. in height. 
This species closely resembles N. triqueter, but has a more ovate form ; the 
other comparisons are given under the description of that species. 
Formation and locality. In concretionary layers in the shales of the Hamilton 
group, on the shore of Lake Erie. 
