DESCRIPTION OF SPECIES 249 



with it also; however, it is often difficult to determine just where the 

 dividing line should be drawn. As thus interpreted the variety tri- 

 carinatus is much less common than P. percarinatus. 



Horizon and locality. Of general distribution throughout the 

 Lower Mercer limestone, c. McArthur member: Vinton County, 

 Moore mine, Locality 84, c. 



Genus Euphemus McCoy 



Euphemus carbonarius (Cox) 

 PL XV, figs. 4, 5 



1855 Bellerophon urii. Norwood and Pratten, Jour. Acad. Nat. Sci. Phil., 2nd Ser., 

 Vol. 3, p. 75, PI. 9, Figs. 65 a-c. (Non B. urii Fleming, 1828) 

 Coal Measures: Galatia and Grayville, Illinois; 5 miles below New Harmony, 

 Indiana. 



1857 Bellerophon carbonarius. Cox, Geol. Surv. Ky., Vol. 3, p. 562. 



Coal Measures: Indiana. 



Remarks. Among the Bellerophon-like forms from the 

 Harrison and Sharon ores, several individuals retain indications of 

 numerous strong, revolving lines and have been identified as Euphemus 

 carbonarius, at least according to the general usage of the term which 

 may in reality include several distinct species or varieties. It is also 

 present in the Boggs member, although rare, but is common in the 

 Lower Mercer and higher Pottsville horizons where it attains a much 

 larger size than in the basal members. 



Horizon and locality. Harrison ore: Jackson County, Locality 1, 

 a. Sharon ore: Scioto County, Locality 2, a. Boggs limestone: 

 Muskingum County, Locality 26, r. Widely distributed in the Lower 

 Mercer limestone, c. Lower Mercer ore: Jackson County, Locality 56, 

 r. McArthur member: Vinton County, Localities 83, 84, c. 



Euphemus nodocarinatus (Hall) 

 PI. XV, figs. 1-3 



1858 Bellerophon nodocarinatus. Hall, Geol. Iowa, Vol. 1, Pt. 2, p. 723, PI. 29, Figs 



15 a-c. 



Coal Measures: Illinois and Iowa. 



Hall's description. "Shell subglobose, expanded at the sides, 

 without umbilicus. Back and sides of the shell, near the aperture, 

 marked by longitudinal or revolving ridges or carinae, about seven or 

 eight on each side of the centre; the two central ones of which, in their 

 extension forward, become more prominent, and form a kind of double 



