NATURAL SCIENCES OF PHILADELPHIA. 327 



little gaping; and the posterior side maj'- have been more or less 

 so, though the specimen is not in a condition to show whether 

 this was the case or not. 



Although I refer this shell, for the present, provisionally, to 

 Dolahra of McCoy, I really have very little idea that it properly 

 belongs to that genus (as typified by Cucullaea angustata of 

 Phillips), to which I have in some other cases referred similar 

 shells, the generic relations of which could not be determined. 

 On the contrary, I strongly suspect that it will hereafter be found 

 necessary to establish a new genus for such forms, when specimens 

 showing the hinge can be examined. If so, I would propose for 

 the group the name Bhxjnchoirojns, in allusion to the sharply 

 carinated character of the beaks in the typical form now under 

 consideration. The group, whatever name may be retained for 

 it, evidently includes Dolahra"? Sterling ensia of Meek and Worthen. 



Specifically, the form under consideration will be distinguished 

 from Z).? Sterlingensis by its much smaller size, and more spiral 

 and much more sharply keeled beaks, as well as by its shorter 

 anterior margin. It must be ver}^ rare, as I have only seen among 

 all the collections the single tj'pical specimen. 



Locality and position. — Cincinnati group, about 175 feet below 

 tops of hills at Cincinnati, Ohio. Mr. Dyer's collection. 



CARDIOMORPHA" OBLIQU ATA, Meek. 



Shell small, rhombic-cordate, very convex, higher than long ; 

 posterior margin sloping rather abruptly, and subtruncate, or a 

 little convex in outline from the posterior extremity'' of the hinge 

 to the posterior basal extremity, which is more or less angular, 

 or narrowly rounded ; basal margin short, nearly straight or a 

 little convex from the posterior basal extremity to the front ; an- 

 terior margin short or truncated from immediately in front of 

 the beaks obliquely downward and backward to the base, which 

 it joins at an obtuse, slightly rounded angle ; binge line very short, 

 ranging at an angle of about fifty degrees to the umbonal axis, 

 and apparently having its margins a little inflected behind the 

 beaks; beaks very prominent, oblique, nearly or quite terminal, 

 and strongly incurved ; posterior umbonal slopes subangular near 

 the points of the beaks, but becoming rounded below, while the 

 dorsal region between this and the hinge is a little concave; an- 

 terior umbonal slopes, forming a kind of ridge that extends, at 

 1872.] 



