390 PALEONTOLOGY OF NEW YORK. 



extremity. Posterior margin vertically sub-truncate. Cardinal line straight. 

 Anterior end short, abruptly rounded below the lunule. 



Valves convex below and posteriorly, gibbous in the middle and umbonal 

 region. 



Beaks sub-anterior, rather prominent, rising a little above the hinge-line. 

 Umbonal slope prominent, scarcely defined, but extending to the post-inferior 

 extremity. Post-cardinal slope broad. 



Surface marked by fine concentric striae, which are abruptly recurved over 

 the umbonal slope, and are fascicled, rising into lamellose elevations. Inte- 

 rior unknown. 



A specimen has a length of 30 mm. and a height of 21 mm. 



This species differs from E. Philipi in its rhomboidal form, truncate posterior 

 end, prominent umbonal slope and lamellose concentric striae. 



Formation and localities. In the sandstones of the Chemung group, at Cold 

 Spring, Cattaraugus county, and doubtfully near Olean, N. Y. 



Edmondia Burlingtonensis. 



PLATE LXIV, PIG. 22 ; AHD PLATE XCV, FIGS. 13, 14. 



JSdtnonrfia BwrZi/ipfoiie/MM, Whitb and Whitkikld. Pi-oc. Bost. Soc. Nat Hist., vol. 8, p. 301. 18')2. 



In part ICdmondia Burlmgtmiensui (White and Whitkibi.d), Hall. Prelim. Notice Lamellibranchiata, 2, 



p. 90. 1870. 

 " " " " " Pal. N. Y., vol. V, pt. 1. Plates and 



Explanations: PL 64, figs. 19-29. 



1883. 



Shell of medium size, ovate-elliptical ; length one-third greater than the 

 height ; basal margin straight in the middle, curving into both extremities. 

 Posterior margin regularly rounded. Cardinal line straight. Anterior end 

 short and regularly rounded. 



Valves moderately convex below and posteriorly, gibbous in the middle 

 and umbonal region. 



Beaks at about the anterior fourth, prominent, incurved. Umbonal slope 

 convex, not defined, merging into the general convexity of the shell before 

 reaching the post-inferior extremity. 



