380 
PALAEONTOLOGY OF NEW YORK. 
curving upward to about the middle of its height, above which it is obliquely 
sub-truncate. Cardinal line straight, more than two-thirds the length of the 
shell, slightly declining posteriorly. Anterior end short, regularly rounded. 
Valves regularly convex in the lower and posterior portion, becoming 
gibbous in the middle and above. 
Beaks at about the anterior third or fourth, rather prominent. Umbonal 
slope sub-angular above, and sometimes continued obscurely to the post-inferior 
extremity. Cincture broad, undefined, extending from the beaks to the base 
anterior to the middle, and producing a flattening of the valve and a slight 
constriction of the basal margin. 
Surface marked by fine concentric striae, with a few, more or less distinct, 
concentric undulations, which become obsolete at about the umbonal angle. 
Interior unknown. 
Three specimens measure respectively 21, 25 and 30 mm. in length, and 
14, 16 and 21 mm. in height. 
This species resembles G. communis, but the concentric undulations are not so 
numerous, the umbonal slope less defined, the posterior end broader and not 
so obliquely truncate above the middle, and the cincture more nearly vertical. 
Formation and localities. In the conglomerate of the Chemung group, at 
Panama, and four miles north of Panama, N. Y.; in the same horizon, at Alle¬ 
ghany Springs, Warren county, Pa.; also in some slialy sandstones, near Sala¬ 
manca, and in the conglomerate, at Portville, N. Y. 
Grammysia duplicata, n. sp. 
PLATE XCIII, FIG. 23. 
Shell small, ovate, abruptly depressed and cuneate behind; length more than 
one-third greater than the height; basal margin regularly curved with a 
scarcely perceptible sinus anterior to the middle. Posterior extremity 
abruptly rounded below and shortly truncate above. Cardinal line straight, 
margined by a narrow escutcheon. Anterior end about one-third the length 
of the shell, pointed, truncate below the lunule. Margin of the lunule nearly 
straight and slightly declining. 
