196 POTTSVILLE FAUNA OF OHIO 



1872 Prothyris elegans. Meek, U. S. Geol. Surv. Nebr., p. 223, PI. 10, Figs. 9 a, b. 

 Upper Coal Measures: Nebraska City, Nebraska. 



Meek's description: "Shell compressed, elongate-oblong, the 

 width being about three and a half times the height; ventral and dorsal 

 margins straight or a little arched; the latter with a faintly defined 

 marginal furrow, below which there is usually an obscure ridge also 

 parallel to the dorsal margin; posterior extremity obliquely subtruncate, 

 the most prominent part being below the middle; beaks compressed, 

 depressed, not distinct from the dorsal margin, and placed about one- 

 eighth or one-ninth the length of the valves behind the anterior ex- 

 tremity; notch of the anterior margin well defined, and extending about 

 half way up from the base, and nearly half the distance back from the 

 front to the beaks; ridge from the inner angle of the notch narrow, flat, 

 and widening slightly from above; anterior margin above the notch 

 rounded, and having the appearance of a flattened ear; surface striae 

 nearly obsolete on the upper half of the valves, and more distinct on 

 the ventral and antero-ventral regions." 



Dimensions. The dimensions of the most perfect of the only two 

 specimens in the collections studied are: length 12.5 mm., height 3.5 

 mm., convexity .7 mm. 



Remarks. This species is represented in the collections of Potts- 

 ville fossils at hand by two individuals, one in almost perfect condi- 

 tion from the Lower Mercer limestone on Flint Ridge, with the valves 

 open but still connected at the hinge line; the other in a less perfect 

 state of preservation from the Upper Mercer limestone. Practically no 

 differences between our species and Meek's can be noted except that 

 the size is only about one-half as great as that of his figured specimen. 

 A form identified by Herrick as P. elegans was likewise obtained on Flint 

 Ridge, 1 but it is also larger than our form. 



Horizon and locality. Lower Mercer limestone: Licking County, 

 Flint Ridge, Locality 47, r. Upper Mercer limestone: Holmes County, 

 Locality 73, r. 



Genus Edmondia De Koninck 

 Edmondia anodontoides (Meek)? 



1875 Solenomya ?? anodontoides. Meek, Pal. Ohio, Vol. II, p. 339, PI. 19, Fig. 11. 



Coal Measures: Newark, Ohio. 

 1887 Solenomya ? anodontoides. Herrick, Bull. Den. Univ., Vol. 2, p. 29, PI. 4, Fig. 10. 



Coal Measures: Flint Ridge. 



Description. A few individual valves from the Lower Mercer 

 member are apparently identical with the Flint Ridge form which 

 Herrick referred to Meek's species Solenomyat? anodontoides. However, 



'Herrick, C. L., Bull. Den. Univ , Vol. 2, p. 32, PI. 4, Fig. 3, 1887. 



