310 3fonograph of the Gasteropoda. 



Cyrtolites elegans — (S. A. Miller). 



Shell convolute, the outer volution on the ventral side receiving, 

 in a narrow groove, the sharp dorsal carina of the inner volution and 

 part of the whorl ; about two volutions somewhat compressed and 

 rapidly enlarging ; sharply carinated on the dorsal margin ; greatest 

 convexity near the umbilical margin ; transverse section somewhat 

 cordiform ; aperture deeply notched on the outer margin. 



Surface marked by numerous, transverse, undulating, subimbricat- 

 ing lamellae, or raised lines, having a slight forward direction from the 

 keel of the shell. 



Diameter of a full-sized spe:'imen, |tli inch ; greatest convexity, 

 jth inch. 



It is distinguished from Cjrtolites compressus, with which it has 

 sometimes been confounded, by being smaller, fewer whorled, having 

 outer whorl embracing more of the inner whorl, and by having un- 

 dulating lamellae much closer, not so regular, nor undulations so great, 



Fig. o\ — CyrtoHtes elegans. Magnified two diameters. 



and havi ag a stronger forward direction from the keel of the shell. 

 It is distinguished from Cyrtolites Dijeri, which it most resembles, by 

 being destitute of the revolving lines or ridges, and having greater 

 flexure in the forward bearing, transverse lamellae. Figure 2, plate 

 13, of the Paleontology of Ohio, though a very poor representation of 

 the specimen, I have reason to think belongs to this species. Prof. 

 Meek says of it : 



" One specimen, in Mr. Dyer's collection, from the Cincinnati rocks, 

 only shows about five of the revolving ridges on each side, and these 

 are very obscure. Its dorsal keel has a marginal line on each side, 

 and shows the raised marks of growth crossing the very narrow space 

 betAveen these to be distinctly curved backward, like those usually 

 seen on the band of Pleurotomaria. In some respects this form 

 resembles C. compressus, Conrad, but it differs materially in having the 

 undulating lamellaj of growth much more crowded, and in the presence 

 of obscure I'evolving lines. It seems to me to be only a variety of the 

 above described species (CyrtoUfes Dyeri)." 



The obscure revolving lines, which Prof, Meek thought he dis- 



