2'Z4: 3'7vr S2}ecie.'< of Fusnih frum Ohia. 



is similar to that of many others, hxit the peculiar zig-zag fea- 

 ture of tlie ornamenting ridges will at once distinguish it from 

 all other described species. Several ornamented, forms of the 

 genus are known from the C'oal-mensures, but their markings 

 consist of nodes, either promiscuously scattered or arranged in 

 patterns. 



Formation and Locality. — In the limestone of the age of the 

 St. Louis and Chester beds of Illinois (Maxville limestone), 

 at Newtonville, Ohio. 



Ilolopca Kcwtoiicnsis, n. sp. 



Pal. O., Vol. Ill, Plate 10, Fig. 12. 



Shell of medium size, ovate in outline and ventricose, with a moderately 

 elevated spire and extremely ventricose volutions, which increase very ra- 

 pidly in bulk from the apex. Volutions three and a half to four in number, 

 Avith strongly rounded surfaces and moderate sutures. Apical angle about 

 seventy degrees. Aperture broad ovate, modified on the inner side by the 

 preceding volution, pointed at the upper end and broadly rounded at the 

 base. Surface of the shell smooth and the substance very thin 



The form of the shell is much like that of a Macroclieilus, 

 but the substance is much thinner than those usually are, and 

 the base of the columella is not prolonged, nor is there a solid 

 axis ; hut sjiecimens 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, N. Y. 



Macroclieilus subcorpulentus, n. sp. 



Pal. O., Vol. Ill, Plate 10, Fig. 14. 



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 



