FOSSILS OF THE HUDSON RIVER GROUP. 



(CINCINNATI FOEMATIONS.) 



BRACHIOPODA. 



Genus LINGULA, Bruguiere. 

 LiNGULA. COVINGTONENSIS (ll. Sp.). 



Plate 1, fig. 1. 



Shell rather below the medium size, broadly and very regularly oval, 

 or elliptical in outline, the breadth and length being as three to four, 

 the apex of the shell scarcely more pointed than the basal margin ; sur- 

 face of the valve very regularly convex transversely, but in a longi- 

 tudinal direction much more prominent toward the beak, becoming 

 gradually more flattened toward the front of the shell. 



Surface of the shell 'marked by sharply elevated, rather distant, con- 

 centric lines ; without other markings of any kind; substance of the shell 

 very thin. 



The example used in description appears to be a dorsal valve, and is 

 probably somewhat shorter, and more rounded posteriorly, than the 

 ventral valve. The shell is somewhat remarkable for its regular oval 

 form and symmetrical outline, and in this respect difiters from any shell 

 of the genus with which we are acquainted. 



Formation and locality : In the Hudson River group, twenty-five to fifty feet above 

 low-water mark, opposite to Cincinnati, Ohio. Collection of U. P. James, Esq. 



Genus LINGULELLA, Salter. 



LiNGULELLA (DiGNOMIA?) CiNCINNATIENSIS (ll. sp.). 



Plate 1, figs. 2, 3. 



Shell above the medium size, sub-angularly ovate in outline; the lat- 

 eral margins of the valves gradually converging from the i:>oint of great- 

 est width, near the lower end, for about one-fourth of the entire length 

 of the shell, measuring on the dorsal valve; from this point the border 



