194 POTTSVILLE FAUNA OF OHIO 



of the specimens are internal molds on which the fine radiating lines 

 characteristic of the species are clearly marked. Tfye Ohio forms show 

 no variations which distinguish them in any way from Meek and 

 Worthen's species. 



Dimensions. The largest specimen in the collections at hand 

 measures: length 30 mm., height 14.5 mm. 



Horizon and locality. Lower Mercer limestone : Muskingum 

 County, Localities 43, 45, r; Licking County, Locality 46, r; Flint Ridge, 

 Localities 47, 48, r. 



Solenomya?? sharonens s n. sp. 

 PL X, figs. 1, 2 



Description. -Shell small, transversely subovate, length about 

 twice the height; convex, point of greatest convexity being about two- 

 fifths the height of the shell from the beak to the inferior margin; beak 

 pointing obliquely forward, incurved, slightly elevated over the cardinal 

 margin, situated about one-third the length of the shell from the anter- 

 ior extremity; cardinal margin equal to one-half the length of the shell, 

 sloping slightly downwards; ventral or inferior margin long, almost 

 straight, rounding abruptly into the posterior extremity which is ob- 

 liquely truncated above and forms an angle of 145 degrees with the 

 hinge line, posterior extremity most extended below the middle of the 

 shell; anterior extremity broadly rounded, slightly concave in outline 

 anterior to the beak, most prominent about the middle of the valve 

 or a little below; a prominent umbonal ridge extending from the beak 

 to the posterior-inferior angle. Surface smooth except for a few obs- 

 cure, concentric lines of growth. 



Dimensions. The measurements of the holotype are: length 13.5 

 mm., length of hinge line 6.2 mm., height 6.8 mm., convexity of right 

 valve 2.4 mm. 



Remarks. There is much doubt concerning the generic identifica- 

 tion of this shell, for it is not very closely allied to any Pennsylvanian 

 genus. It is very possible that it does not belong to the genus Solenomya 

 which lacks the prominent beak and umbonal development of the form 

 under discussion; however, as our specimens appear most closely related 

 to Solenomya, it seems best to place them provisionally with that 

 genus. One would scarcely be justified in establishing a new genus 

 from the material at hand which does not show the characters of the 

 hinge and interior adequately. The form is confined to one locality of 

 the Sharon ore and has been found only as internal casts. 



Horizon and locality. Sharon ore: Lick Run, Scioto County, Lo- 

 cality 2, r. 



