DESCRIPTION OP SPECIES 199 



However, his specimen of S. ? anodontoides differs notably from typical 

 S. ? anodontoides of Meek in lacking the anteriorly converging margins 

 and the acute, prominently projecting anterior extremity, and prob- 

 ably represents a different species. 



Horizon and locality. Lower Mercer limestone: Muskingum 

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

 47, 48, r. 



Edmondia ovata Meek and Worthen 

 PI. X, figs. 8, 9 



1873 Edmondia ovata. Meek and Worthen, Geol. Surv. 111., Vol. 5, PI. 26, Fig. 13. 



Coal Measures. 



1874 Edmondia ovata. Meek, Am. Jour. Sci., 3d Ser., Vol. 7, p. 580. 



Description. Shells resembling both Edmondia ovata and E. sub- 

 truncata are common in the Lower Mercer limestone, especially in 

 Muskingum and Licking counties, and also in the Me Arthur member. 

 The figured specimen is typical of this group of fossils. From E. ovata, 

 to which it seems most closely related, it differs in being slightly less 

 elongate with the beak a little more anterior; from E. subtruncata in 

 having the posterior outline a little less truncated. However, the dif- 

 ferences between E. ovata and E. sublruncata are so slight that, as 

 intimated by Meek, the two species may be identical. The surface of 

 our form is marked by coarse, irregular, concentric wrinkles with the 

 entire shell covered with very fine concentric lines. 



Dimensions. Figure 9 on Plate X measures: length 29 mm., 

 height 20 mm., convexity of right valve 5.5 mm. 



Horizon and locality. Lower Mercer member: Perry County, 

 Locality 35, r; Muskingum County, Locality 45, c; Licking County, 

 Localities 46, r, Flint Ridge, 47 (c), 49 (r). Upper Mercer member: 

 Perry County, Locality 63, r. McArthur member: Vinton County, 

 Locality 84, c. 



Edmondia reflexa Meek 



1872 Edmondia reflexa. Meek, U. S. Geol. Surv. Nebraska, p. 213, PI. 10, Figs. 6a, b; 

 PI. 4, Fig. 7. 

 Upper Coal Measures: Nebraska City, Nebraska. 



Description. This species of Edmondia is present in the Pottsville 

 formation of this State in and above the Lower Mercer limestone, and 

 is fairly common in the latter member and in the McArthur limestone. 

 The shell is marked by very fine concentric undulations on which faint 

 traces of radiating lirae are sometimes visible. 



