212 POTTSVILLB FAUNA OP OHIO 



cardinal margin. The surface is smooth except for a few thin, elevated 

 lines parallel to the ventral and posterior margins. 



Remarks. This species is rare in the Pennsylvanian rocks of Ohio, 

 and there is no record of its occurrence at any horizon as commonly 

 as in the Boggs member. The type specimen was obtained from the 

 upper Coal Measures of Nebraska, at which horizon it also occurs in 

 Iowa and Missouri. Meek, however, described and figured the same 

 species from the lower Coal Measures of Ohio, but he does not state the 

 exact horizon or locality from which the figured specimen came. Her- 

 rick also figures a specimen from Flint Ridge (Lower Mercer member) 

 which he provisionally refers to the same species. 1 



Horizon and locality. Boggs member: Muskingum County, Lo- 

 cality 26, c. Lower Mercer limestone: Perry County, Locality 35, r; 

 Licking County, Locality 48, r. 



Genus Pteria Scopoli 

 Pteria ohioense (Herrick) 



1887 Gervillia ? ohioensis. Herrick, Bull. Den. Univ., Vol. 2, p. 36, PL 4, Fig. 3; 



PL 3, Fig. 12. 



Coal Measures: Flint Ridge, Ohio. 

 1887 Avicula (Gervillia) ohioensis. Herrick, Bull. Den. Univ., Vol. 2, p. 145, PL 14, 



Fig. 22. 



Coal Measures: Flint Ridge, Ohio. 



Herrick's description. "The upper outline is nearly straight; beak 

 distant nearly one-third the length from the anterior margin; posterior 

 wing greatly produced, posterior margin deeply sinuous; posterior, pro- 

 duced part of shell keeled; anterior wing acute, its margin very oblique 

 and slightly curved to its junction with the lower margin, with which 

 it forms a continuous symmetrical curve. Hinge line, .65 (inches); 

 height .45, greatest length .85. The surface is marked by rather obvi- 

 ous concentric lines. The postero-inferior projection is greater than 

 that of the hinge line. From A. longa, which it most resembles, it 

 differs in being not only larger, but less produced posteriorly, the post- 

 erior sinus is much less and the anterior part of the shell does not appear 

 to have the oblique sulcus described for that species." 



Remarks. This species is of relatively wide distribution in the 

 Lower Mercer and Me Arthur limestones; although the number of in- 

 dividuals obtained from any one locality is small; the specimens studied 

 are all imperfect in one way or another, probably due to the thin, fragile 

 character of the shell. No important differences were noted between 

 our form and Herrick's species. 



A few specimens from the Black Flint member have likewise been 

 derrick, C. L., Bull. Den. Univ., Vol. 2. p. 38, PL 1, Fig. 20, 1887. 



