﻿76 NORWOOD AND PRATTEN, NOTICE OF FOSSILS FROM THE 



Geological Position and Locality. — This species appears to be very rare, having 

 been found only at Rock Creek, Williamson county, Illinois, where it occurs in a 

 black, carbonaceous shale, belonging to the coal measures. 



Explanation of the Figure. — PL IX. fig. 8. View of the front and left side of an adult 

 specimen. 



Illinois State Collection. 



MACROCHEILUS. 



M. inhabilis, Morton, sp. PL IX. fig. 9, a, b. 



Fusus (?) inhabilis, Morton. — " American Journal of Science and Art" 1st Series, 

 Vol. xxix., p. 150, fig. 14, plate 3. 



This species, which was found in 1834, by Dr. S. P. Hildreth, of Marietta, Ohio, 

 occupying the same position it does further west, was referred by Dr. S. G. Morton to 

 the genus " Fusus f and published without any adequate description. Its occurrence 

 in the same geological horizon over so large a district of country, gives it an impor- 

 tance which renders it desirable to supply the deficiency. 



Shell nearly globular ; spire short, forming an angle of 105°. Whorls five; the 

 body whorl very large and inflated, while the remainder are comparatively small, and 

 occupy only one seventh of the total length of the shell. Aperture semi-elliptical ; 

 much longer than wide. Columella rather long, and furnished with a distinct fold. 

 The length of a large specimen is 1 8-1 0th inches. This species resembles somewhat 

 the M. MicJwtianus of De Koninck, but diners from it in its greater size, and in having 

 but five whorls ; that species having six. 



Geological Position and Locality. — This species is found in the middle of the coal 

 measures at Grayville and Galatia, Illinois, and rather more abundantly, but of 

 smaller size, in the shales of the same formation in Posey county, Indiana. It also 

 occurs, according to Dr. Hildreth in the same part of the coal series of Ohio. 



Illinois State Collection. 



Explanation of the Figures. — PL IX. fig. 9, a. Front view of a large individual. 



Fig. 9, h. — Back view of the same. 



NATICA. 



N. ventrica, nob. — PI. IX. fig. 10, a, b. 



Shell small, globose, ventricose ; spire very short, consisting of four whorls, the 

 body whorl being very large, and occupying six sevenths of the whole length of the 

 shell. The upper portion of each whorl is ornamented by a series of lines radiating 

 from the axis of the shell, which proceed outwards from the suture and then slightly 



