478 GEOLOGY OF OHIO. 



columella is not prolonged, nor is there a solid axis; but specimens show 

 satisfactory evidence of having been distinctly and largely umbilicated. 

 Formation and Locality— -In the Maxville limestone (Chester), at 

 Newtonville, Ohio. Collection of Columbia College, New York. 



Genus MACROCHEILUS Phillips. 



Macrocheilus subcorpulcntus. 



Plate X, fig. 14. 



Macrocheilus subcorpulentus Whitf., Ann. N. Y. Acad. Sci., 1882, p. 224. 



Shell small, the specimens observed not exceeding five-eighths of an inch in 

 length, and the diameter rather exceeding half the length ; spire conical, the apical 

 angle being about fifty degrees. Volutions about three or three and a half, rapidly 

 increasing in diameter and very ventricose, the last one forming more than half the 

 length and much the greater bulk of the shell; suture deep and well marked. 

 Aperture ovate, short, and oblique. Surface of the shell smooth. Columella not 

 seen. 



This species is rather closely related to several forms which have 

 been described from the Coal Measures of the Western States, but differs 

 in the form of the volutions somewhat from any, and in the more regular 

 tapering spire — those mostly having the body-volutions proportionally 

 enlarged. 



Formation and Locality. — In the Maxville limestone (Chester and St. 

 Louis groups), at Newtonville, Ohio. Collected by Prof. E. B. Andrews. 



Genus POLYPHEMOPSIS Portlock. 



Polyphemopsis melanoides. 



Plate X, fig. 13. 



Polyphemopsis melanoides Whitf., Ann. N. Y. Acad. Sci., 1832, p. 225. 



Shell rather below a medium size, elongate-fusiform ; the length nearly twice 

 and a half the greatest diameter, when not compressed; spire elevated, pointed at 

 the apex, the apical angle being about thirty-five degrees when uncompressed. The 

 specimen figured gives on measurement thirty degrees in the line of compression, 

 and forty degrees in the opposite direction. Volutions about five and a half, gradu- 

 ally increasing in size, moderately and evenly convex, with distinct sutures. Aper- 

 ture elongate ovate, widest across the middle, rounded and effuse below and pointed 

 above. Columella not observed. Surface apparently smooth. 



This species nearly of the form of M. fusiforme Hall ( Geol. Rept, 

 Iowa, vol. i, part 2), from the Coal Measures of Iowa, but is considerably 

 more slender. It is possible it may not properly belong to the genus, as 

 the columella has not been closely observed ; but so far as can be deter- 

 mined, it appears to be twisted. 



Formation and Locality. — In the Maxville limestone, at Newtonville, 

 Ohio. Collected by Prof. E. B. Andrews. 



