376 
PALAEONTOLOGY OF NEW YORK. 
d. elongaia. 
Grammysia precursor. 
PLATE LIX, FIG. 1. 
Grammysia precursor, Hall. Prelim. Notice Lamellibranchiata, 2, p. 54. 1S70. 
Grammysia (Leptodomus?) prwcursor, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 59, 
fig. 1. 1883. 
Shell small, transversely ovate; length nearly twice the height; basal margin 
regularly curved with a slight sinus anterior to the middle. Posterior ex¬ 
tremity sub-angular. Cardinal line straight. Anterior end short, narrowly 
rounded below the distinct lunule. 
Valves regularly convex below and posteriorly, becoming very gibbous in 
the middle and above. 
Beaks sub-anterior, prominent and strongly incurved. Umbonal slope 
sub-angular. A shallow, indistinct cincture crosses the valve about one-third 
of its length from the anterior end. 
Surface of the valves marked by numerous concentric folds, which are 
sharp on the anterior end of the shell, becoming more distant and rounded 
toward the umbonal slope, and partially obsolete near the posterior extrem¬ 
ity, with a few interstitial ridges rising anterior to the middle of the valve. 
Some portions of the shell still remaining on the cast show fine concentric 
strife, with finer radiating lines. Interior unknown. 
The specimen described has a length of 30 mm. and a height of 16 mm. 
In some of its characters this species bears a slight resemblance to G. arcuata, 
but the undulations are finer, the valves narrower behind and marked by a 
distinct sub-angular umbonal slope. 
Formation and locality. In the Schoharie grit, at Schoharie, N. Y. 
Grammysia secunda. 
PLATE LIX, FIGS. 2, 3. 
Grammysia secunda, Hall. Prelim. Notice Lamellibranchiata, 2, p. 54. 1870. 
“ “ “ Pal. N. Y’., vol. v, pt. 1. Plates and Explanations: PI. 59, figs. 2, 3 (4, 5 in 
error). 1883. 
Shell small, sub-elliptical; length about twice the height; basal margin gently 
curving, with a distinct sinuosity near the anterior end. Posterior extremity 
