466 PALEONTOLOGY OF NEW YORK. 



striate. Anterior to the cincture the surface of the shell is marked by fine 

 granulaj or minute pustules. 



Three specimens measure respectively 33, 62 and 105 mm. in length, and 

 13, 22 and 30 mm. in height. 



As compared with C. clongata, the shell is more distinctly recurved, the cinc- 

 ture is stronger and the granulose striae are finer. It differs from all other 

 species in the strong irregular concentric undulations on the body of the shell. 



Formation and localities. In the Hamilton group, at Sherburne, Pratt's falls 

 and Delphi ; and on the shore of Canandaigua lake, N. Y. Mr. Conrad cites 

 the species from near Smyrna, Chenango county, N. Y. 



CiMITARIA ELONGATA. 



PLATE LXXVII, FIGS. 5-8. 



Cypricardlteji ehmgatiu), Conrad. Geol. Surv. N. Y., Ann. Rep., p. 51. 1841. 

 Cimitaria elongata (Conrad), Hall. Prelim. Notice Lamellibrancliiafa, 2, p. (')9. 1870. 



" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 77, figs. ii-S. 



1883. 



Shell below the medium size, as compared with other species of the genus, 

 sub-ensiform ; length about two and one-half times the height ; basal margin 

 gently curved, slightly sinuate anterior to the middle. Posterior extremity 

 obliquely truncate above. Cardinal line es.sentially .straight. Anterior end 

 short, obliquely truncate from the beak, abruptly rounded below. Lunule 

 very long and sharply defined. 



Valves depressed-convex in the lower and posterior portions, and gibbous 

 in the umbonal region. 



Beaks sub-anterior, prominent, appressed and incurved, Umbonal slope 

 obtusely sub-angular, extending to the posterior extremity. Post-cardinal 

 slope concave anteriorly, and becoming flattened at the posterior extremity. 

 Cincture a broa<l undefined depression, extending from the beak to the base 

 of the shell, giving a slight sinuosity to the margin. 



Surface marked by fine concentric striae, which .an; somewhat irregularly 

 fasciculate, especi.ally on the anterior and posterior portions of the shell. 



