,Vj PA I..K<)\ TOLOGY OF NEW TORE. 



below tin- suture, and moderately rounded below, leaving a distinct angle, over 

 which the stria 1 pass without deflection. On the last volution towards the 

 aperture this angularity of the upper side becomes gradually obsolete, while 

 the liase of the volution is marked by a distinct carina in continuation of the 

 suture-line. 



In figures 11 and 12 the penultimate volution, as represented, is not quite 

 sufficiently convex, while the angularity at the base of the last volution is con- 

 spicuous. In the specimen, fig. 13, there is no perceptible angularity of the last 

 volution ; while in the specimen represented in figure 14 there is an obtuse 

 angularity, which appears more as if due to accidental pressure from above, 

 flattening the base of the last volution. In the same specimen, however, there 

 is a distinct angularity and flattened space on the summit of the next two 

 volutions above. In the specimen, fig. 15, the upper volutions are moderately 

 rotund, and the last one rounded and ventricose. 



From this form to those figured on plate 12, as Callonema Lichas, there seems 

 to me an easy passage. However, I have, for the present, preserved the latter 

 name and references, which, if the species prove identical, will supersede the 

 name of bellatula. 



Formation and localities. In limestone of the age of the Upper Helderberg, 

 near Columbus, Ohio, and at the Falls of the Ohio river. 



Callonema Lichas. . 



PLATE XII, FIGS. 19-22. 



PUUyo8toma Lichas, Haxl. Fourteenth Kep. N. Y. State Cab. Nat. Hist., p. 106. 1861. 

 Isonema " " Illustrations of Devonian Fossils : Gasteropoda, pi. 12. 1876. 



Shell obliquely subconical ovate ; spire elevated. Volutions about four or 

 more, rounded upon the exterior, the earlier ones moderately expanding, 

 and the last one becoming very ventricose. Aperture subovate, extended 

 below. 



Surface marked by fine even stria? of growth, which, on the last volution, 

 continue over the periphery and disappear in the umbilicus. 



