264 POTTSVILLE FAUNA OF OHIO 



Sphaerodoma regularis (Cox) 



1857 Loxonema regularis. Cox, Geol. Surv. Ky., Vol. 3, p. 566, PI. 8, Fig. 2. 



Coal Measures: Da vies 3 County, Kentucky. 



Description. Completely flattened remains and impressions of a 

 high-spired gastropod of median size resembling Sphaerodoma regularis 

 are somewhat common in the black shale above the Lower Mercer 

 limestone near East Greenville, Stark County. The lower volution is 

 wanting on the specimens examined, so that the characters of the 

 aperture and columnella are unknown. Twelve volutions which in- 

 crease gradually and regularly in size are generally present. The form 

 is here tentatively referred to S. regularis in the absence of data which 

 would render the identification unlikely. A number of complete forms 

 from the railroad cut at Somerset and from Flint Ridge, also from the 

 Lower Mercer limestone, are preserved sufficiently well to be identified 

 with more confidence. 



Horizon and locality. Lower Mercer limestone: Perry County, 

 Locality 35, c; Licking County, Bald Knob, Locality 46, r; Stark County, 

 Locality 52, c. 



Sphaerodoma ventricosa (Hall) 



1858 Macrocheilus ventricosus. Hall, Kept. Iowa Geol. Surv.,- Vol. 1, Pt. 2, PI. 29, 



Fig. 8. (Non Phasianella ventricosa Goldfuss, 1841.) 

 Lower Coal Measures: Des Moines Valley, Iowa. 



1913 Sphaerodoma ventricosa. Girty, U. S. Geol. Surv., Bull. 544, p. 213, PI. XXIV, 

 Figs. 4, 4a. 

 Wewoka formation: Oklahoma. 



Remarks. A single small individual from the Upper Mercer lime- 

 stone has been referred to Sphaerodoma ventricosa although the aper- 

 ture and columnella could not be observed. However, the height of 

 the spire and the number and shape of the volutions appear identical 

 with that species. About half a dozen specimens from the Lower 

 Mercer limestone in a fairly good condition of preservation have been 

 identified with S. ventricosa with more confidence. 



Dimensions. A specimen from the Lower Mercer limestone 

 measures: height of shell 13 mm., height of last volution 7 mm., width 

 7 mm. 



Horizon and locality. Lower Mercer limestone : Muskingurn 

 County, Locality 29, r. Upper Mercer limestone: Holmes County, 

 Locality 73, r. 



