140 Cincinnati Society of Natural History 



nearest the suture on the apical side is rather distant from that 

 suture, the next three interspaces are not as wide, and the last 

 three, as far as the lower suture, are distinctly narrower. Below 

 the periphery corresponding to the suture line, the last or largest 

 whorl possesses four or five additional carinae, less distinct than 

 those above, and gradually becoming less distinct the more distant 

 they are from the periphery. The spaces between the carinse are 

 occupied by additional sharp striae, of which there are usually four 

 in the wider spaces, the central one being somewhat stronger; 

 only one additional striation occurs as a rule in the narrower 

 spaces, and similar striations occur on the lower slope of the body 

 whorl below the lowest striations which can still be called carinae. 

 However, on this lowest part of the body whorl, the transverse 

 striations are more prominent than the revolving striations. The 

 inner lip of the aperture is nearly vertical. The variety evidently 

 is closely related to Cyclonema varicosum, Hall, but it is a dis- 

 tinctly smaller form, the largest specimens found so far not ex- 

 ceeding 20 mm. in width, and the revolving carinae are corre- 

 spondingly less prominent. The chief distinguishing feature is 

 the lower spire, producing a relatively wider and flatter shell. The 

 most numerous specimens occur at the railroad cut 59.1 miles from 

 Ludlow ; other specimens occur at 60.3, 59.8, 59.7, 59.5, 59.3, 58.9, 

 58.8, 58.3, 55.7, 54.6, and 54.3 miles from Ludlow. Cyclonema cin- 

 cinnatense was described originally by S. A. Miller from strata 

 below the Fulton layer at Cincinnati and in the immediate vicinity. 

 Ulrich regarded it as identical with Cyclonema varicosum, and it is 

 listed under the latter name by Nickles. 



38 — Tetranota obsoleta, Ulrich and Scofield — A species of 

 Tetranofa is very common at the railroad cut 59.1 miles from Lud- 

 low. It occurs also at 59.7. It is similar to Tetranota obsoleta in 

 the distinctness of the four revolving ridges on the younger parts 

 of the shell, and their comparative indistinctness on the last volu- 

 tion. Usually the lateral volutions are almost obsolete on the last 

 volution, and the two central volutions are united so as to form a 

 convex central ridge, but occasionally specimens are found in which 

 these adolescent features remain fairly distinct, even in fully ma- 



36 



