LAMELLIBRANCHIA TA. 
489 
Pal^anatina solenoides, n. sp. 
PLATE LXXIX, FIGS. 3S, 3>J. 
In part Palceanatina typa, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 79, fig's. 26-39. 
Shell elongate, sub-quadrate; ventral and dorsal margins sub-parallel; length 
two and one-half times the height; basal margin nearly straight or a little 
contracted anterior to the middle. Posterior extremity almost vertically 
truncate. Cardinal line straight. Anterior end short, the upper side 
extended in continuation with the cardinal line, and curving below. 
Left valve regularly convex, scarcely gibbous in the umbonal region. 
Right valve depressed-convex throughout. 
Beaks at about the anterior fourth, that of the left valve rising above the 
hinge-line and incurved; in the right valve scarcely rising above the cardi¬ 
nal line. In the left valve there is a flattening of the beak, and a broad 
undefined depression below, extending to the basal margin. Umbonal slope 
of the left valve obtusely sub-angular for a short distance from the beak, 
merging into the general convexity before reaching the middle of the shell. 
In the right valve the umbonal ridge is obsolete. Cardinal slope not dis¬ 
tinct from the general convexity. 
Surface marked by fine concentric striae, which become fasciculate on the 
posterior slope, and are nearly vertical to the hinge-line. 
The ligamental area is comparatively short, about one-fourth the length of 
the shell. 
The specimen described has a length of about 42 mm. and a height of 17 
■ mm. 
This shell is more elongate than the preceding, the cardinal margin is more 
extended and straighter, the posterior end truncate ; the umbonal ridge is less 
defined, and there is no evidence of a fold upon the post-cardinal slope. 
Formation and locality. In a conglomerate of the Chemung group, near Port- 
ville, Alleghany county, N. Y. 
