494 PALEONTOLOGY OF NEW YORK. 



Right valve depressed-convex, slightly concave from the beak to the base 

 in a broad undefined depression. Left valve unknown. 



Beaks behind the anterior third, low, inconspicuous. Umbonal slope 

 defined, prominent, extending to the post-inferior angle, which is abruptly 

 rounded, limited on the up; :r side by a distinct furrow, which produces a 

 slight sinuosity in the margin. Post-cardinal slope broad. 



Surface marked by fine concentric striae. 



A specimen has a length of 53 mm. and a height of 30 mm. at the poste- 

 rior end, and of 20 mm. at the beak. 



This shell is distinguished by its large size, extremely long cardinal line, the 

 retrally truncate anterior end, and the sinuate posterior extremity. 



Formation and locality. In the upper part of the Chemung group, at Warren, 

 Pa. 



GLOSSITES, N. G. 

 Glossites teretis, n. sp. 



PLATE XCVI, FIG. 18. 



Shell below the medium size, elongate, sub-elliptical, narrower in front ; length 

 more than twice the greatest height ; basal margin broadly curved, sinuate 

 anterior to the middle. Posterior extremity narrowly rounded, and with the 

 margin above sloping acutely forward. Cardinal line slightly oblique, about 

 half the length of the shell. Anterior end short, descending from the beaks 

 and narrowly rounded below. 



Valves of moderate convexity below, becoming gibbous in the umbonal 

 region. 



Beaks sub-anterior, small, rising but little above the hinge-line. Umbonal 

 slope convex, continued to the post-inferior extremity. Cardinal slope nar- 

 row. There is a shallow, undefined cincture extending from the beaks to 

 the anterior part of the basal margin. 



Surface marked by fine striae of growth which are aggregated into irregu- 

 lar fascicles on the body of the shell and umbonal slope. Interior unknown. 



