OF DENISON UNIVERSITY. 89 



these, well-preserved specimens show less distinct revolving strias upon 

 the sides, especially near the umbilicus. 



We have experienced much difficulty in identifying our Bellero- 

 phons. This species is poorly re[)resented and very variable. The 

 form which is referred with confidence to B. cyrtolites, is found in the 

 shales below congl. I, and is about the size of the species quoted. 

 The form is exactly as in the Illinois types. Very careful examination 

 is necessary to discover the revolving lines; 13 is the maximum ob- 

 served diameter. 



A larger form occurs in the shales below congl. II. in which the 

 concavity of the sides is more marked, as also the abruptness of the 

 descent to the umbilicus. These are all in the form of casts preserv- 

 ing impressed lines of growth; 22 mm. is a common dimension for the 

 greatest diameter. Above congl. II, in a blue friable shale, speci- 

 mens more like the type are again found. 



The second variety has been collected at Newark, Rushville and 

 Granville, and has been discriminated as B. cribristriatiis. 



There are from 6 to 10 striie in the space of one tenth inch near 

 the aperture Dorso-ventral diameter of aperture perhaps 12-15 ""'""'» 

 transverse diameter 1012. 



Belleroplion> galericidatits, W>"- 

 (Plate IX, Fig. 32.) 



'•Shell small, globose, involute, carinate, ex-umbilicate, longitudi- 

 nally striate, and deeply notched. Dorsum broadly and regularly 

 rounded, without any evidences of a band except in approaching the 

 aperture of adult shells, where a rather broad band, with ventrally 

 concave incremental lines can be faintly traced. Aperture crescentic, 

 not suddenly exi).\nded, strongly auriculate, with the ears hanging de 

 tached from the inner whorl. Notch infundibuliform, deep and broad, 

 obtuse, its sides reaching the tips of the auriculations. I'mbilicus 

 closed, scarcely indented. Dorsal and dorso lateral surface marked 

 by about 28 longitudinal, sharply raised strias, separated by much 

 wider flutings and not percepti*-ly modified by dorsal band until within 

 half of a whorl of the aperture of the adult shell, when the two mid- 

 dle striae become slightly raised and enlarged and tlie entire set simul- 

 taneously die away. Between these striai and the umbilical point sim- 



