490 
PALEONTOLOGY OF NEW YORK. 
PAL7EANATINA ANGUSTA, n. Sp. 
PLATE LXXIX, FIGS. 29-34. 
In part Palwanatina typa. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 79, figs. 26-39. 
1883. 
Shell small, elongate, narrowly elliptical or sub-cylindrical; length from two 
and a half to three times the height; basal margin straight or slightly sinu¬ 
ate. Posterior extremity obliquely truncate or regularly rounded. Cardinal 
line straight or slightly declining posteriorly. Anterior end narrow, rounded. 
Left valve gibbous in the umbonal region. Right valve less gibbous and 
more depressed below the umbonal ridge. 
Beaks between the anterior third and fourth, small, scarcely rising above 
the hinge. Umbonal slope obtusely sub-angular, extending to the post¬ 
inferior extremity. Post-cardinal slope flat or concave, with a fold in the 
left valve, a feature not observed in the right valve. There is a shallow 
undefined depression extending from the umbo to the base, scarcely affecting 
the margin. 
Surface marked by fine concentric striae, which become fasciculate on the 
posterior end of the shell. 
Five specimens measure respectively 21, 24, 26.5, 30 and 32 mm. in 
length, and 9, 10, 10, 10 and 10 mm. in height. 
Compared with either of the preceding species this shell is comparatively 
smaller, more elongate, and the difference in the convexity of the valves is less 
conspicuous. 
Farther collections may show the necessity of separating such specimens as 
are represented in figure 30 of plate lxxix. 
Formation and locality. In a conglomerate of the Chemung group,, near Port- 
ville, Alleghany county, N. Y. 
