376 PALEONTOLOGY OF NEW YORK. 



d. elongaia. 



GrAMMYSIA PRiECCRSOR. 

 I'LATE LIX, FIG. 1. 



Orammy-^ia prcuiirsor. Hall. Prelim. Notice Lamellibranchiata, 2, p. 54. 1S70. 



Orammyaia (Le]>todtnniuif) pracursor, Hull. 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 

 regulai'ly 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 

 striae, with finer radiating lines. Interior unknown. 



The specimen described has a length of 30 mm. and a height of IG 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, X 



Orammyfia secunda. Hall. Prelim. Notice Lamcllibranchiata, 2, p. 54. 1870. 



Pal. N. Y., vol. V, pt. 1. Plat<>» and Explanations: PI. 59, ftgs. 2, 3 (4, 5 in 

 en-or). 1883. 



Shell small, sub-elliptical ; length about twice the height ; basal margin gently 

 curving, with a distinct sinuosity near the anterior end. Posterior extremity 



