336 PALEONTOLOGY OF OHIO. 



YoLDiA (Paleoneilo ?) CARBONAEiA, Meek. 



Plate 19, fig. 5. 



Yoldia [Palseomilof) carbonaria, Meek (1871); List Carb. Foss. West Virginia, 6 (Ext. 

 from Rep. Regents University of West Virginia). 



This species is much more convex and elongated than the last, and 

 has its beaks located farther forward, its anterior margin more narrowly 

 rounded, and its posterior dorsal slope straighter and more declining. 

 Its dorsal margin also wants the carinate and sulcate character of that 

 shell, from which it also differs in having its posterior basal margin 

 slightly sinuous, instead of regularly convex, and its surface without 

 fine, regular, concentric strise. 



Length, 0.84 inch; height, 0.38 inch. 



The hinge and interior of this shell are unknown, but it has the exter- 

 nal characters of form, etc., of some of the species included in the group 

 Palseoneilo. 



Locality and position Same as last. 



Genus SCHIZODUS, King, 1844. 

 (Ann, Mag. Nat. Hist., XIV., 313.) 



ScHizoDus CUNEATUS, Meek. 



Plate 20, fig. 7. 



Shell attaining a large size, ovate-subtrigonal, rather decidedly com- 

 pressed, the greatest convexity being in the anterior and umbonal regions ; 

 anterior side very short, obliquely subtruncated above, and broadly 

 rounded from near the beaks into the base; basal margin longitudinally 

 semiovate, being most prominent anteriorly, somewhat straightened and 

 ascending obliquely behind to the abruptly rounded or subangular pos- 

 terior basal extremity; posterior side long, cuneate, somewhat narrowed, 

 obliquely truncated above from the end of the hinge to the posterior 

 basal extremity ; hinge line straight behind the beaks, where it is about 

 one-third as long as the valves and a little declining backward ; beaks 

 prominent, erect, incurved, and located only about one-fourth the entire 

 length of the valves from the anterior margin ; posterior umbonal slopes 

 subangular near the beaks, and continued thence as a rounded promi- 

 nence obliquely to the posterior basal extremity. Surface smooth, or only 

 showing obscure lines of growth. 



Length, 2.15 inches; height to top of beaks, 1.62 inches; convexity, 

 0.72 inch. 



