92 PALEONTOLOGY OF OHIO. 



negleda. Not having then seen his figures, and the species having been 

 described from very imperfect material, we were not able to determine 

 fully the specific relations. On strictly comparing it, however, with his 

 description and figure, as given in the first volume Palasontology of Ohio, 

 pi. 12, fig. 8, it proves to be a very distinct species. Mr. Meek describes 

 his species as " about one-third longer than high, rather distinctly com- 

 pressed, most convex and most elevated in the central and umbonal 

 region"— also as having the basal line forming a "nearly semi-oval 

 curve, its most prominent part being near the middle" — while the 

 species under consideration is about twice as long as high, not at all 

 compressed, but, on the contrary, extremely ventricose, except near the 

 posterior extremity, with the central portion not so prominent as the 

 umbonal ridge, and with the basal line broadly sinuate, instead of form- 

 ing a semi-oval curve, the depression in the basal line being just where 

 that one is the most prominent. Several specimens of this species ex- 

 amined preserve these features well marked. Another species, associated 

 with this one in the same position and locality, has many more charac- 

 ters agreeing with Mr. Meek's description and figure, a small individual 

 of which is represented on the plate, under the name adopted by him, 

 for comparison. Among the collections of Prof. Edward Orton there is a 

 specimen nearly twice the size of the one figured. 



Formation and locality : In the shales of the Hudson River group, near Waynes- 

 ville, Ohio. 



CUNEAMYA SCAPHA (n, Sp.). 



Plate 2, fig. 12. 



Shell of medium size, transversely elongate ovate, largest at the an- 

 terior end, with prominent, incurved, nearly terminal beaks ; cardinal 

 and basal margins parallel, or nearly so ; jDOsterior end broad, obliquely 

 truncate, and rounded from the extremity of the hinge line to the 

 postero-basal angle; anterior end very slightly prolonged beyond the 

 beaks, the upper margins inflected, forming a rather large sized lunula, 

 below which the border slopes abruptly backwards to the basal line, 

 forming a somewhat obtuse or undefined angle at their junction ; basal 

 line gibbous at the anterior and posterior third of its length, flattened or 

 somewhat sinuate in the middle. Surface of the valves convex for the 

 anterior two-thirds of the length and to the crest of the umbonal ridge, 

 beyond which it slopes abruptly to the postero-cardinal margin, being 



