1062 THE PALEONTOLOGY OF MINNESOTA. 



[Cyclonema sublaave. 



CYCLONEMA STJBL^EVE, n. sp. (Ulrich.) 



PLATE LXXVIII. PIGS. 48 and 49. 



The form of the shell and whorls in this species and the variations in the bight of the spire and in 

 the expansion of the whorls, is precisely as in C. mediak, from which it is distinguished by its occasionally 

 obsolete and always much thinner revolving striae. In many specimens the upper half or more of the 

 outer slope of the whorls is quite free of spiral lines, in others they are obscurely indicated. On the lower 

 half the lines become gradually more distinct (occasionally the first beneath the smooth space is the 

 strongest of all), but they are never very prominent or sharp. On the body whorl, where they are from 

 one-third to one-half a millimeter apart, a partial alternation in size is usually apparent. C. simulans has 

 more abruptly impressed sutures and more distant revolving lines. 



Formation and locality Not uncommon in the lower half of the Lorraine group at several localities 

 in the vicinity of Cincinnati. 



Collection. E. O. Dlrich. (About 70 specimens.) 



CYCLONEMA TBANSVEESUM, n. sp. (Ulrich.) 



PLATE LXXXII, FIGS. 65-67. 



This may be an extreme variety of C. sublceve, but the six specimens which we refer here look so 

 much alike and so different from the prevailing varieties of that species, that very few if any would hesi- 

 tate in pronouncing them distinct. The specimens vary in width from 17 to 30 mm. The spire is imper- 

 fect in all, but, judging from what remains, the total hight cannot have equalled the width. Apparently 

 it was about a sixth less. The apical angle is about 85. The last whorl expands very rapidly, is gently 

 convex in the upper slope and on the base, and abruptly rounded at the periphery. The aperture is very 

 oblique and unusually large in a basal view, the excavated inner lip very wide. The surface is more or 

 less strongly marked with oblique lines and wrinkles of growth without a trace of revolving lines except 

 on the smallest specimen. In this the inner half of the last whorl presents several very obscure revolving 

 lines on the lower half of the outer slope. 



Aside from the almost total absence of revolving lines, the rapid expansion of the last whorl and 

 shallow suture will distinguish C. transversum from most of the preceding species of the genus. 



Formation and locality. Lower half of the Lorraine group, Covington, Kentucky, and Cincinnati, 

 Ohio. 



Colkction. E. O. Ulrich. 



CYCLONEMA GRACILE, n. sp. (Ulrich.) 



PLATE LXXXII, FIGS. 85-l. 



Shell scarcely attaining medium size, perfect specimens consisting of five or six, more or less slender, 

 rounded whorls; excepting the minute apical turns, the whorls increase regularly in size; either the whole 

 or only the lower part of the whorls may be covered with fine revolving stria?, or these may be wanting 

 entirely; when present a glass is usually necessary to show them clearly; lines of growth having the usual 

 direction, very fine, scarcely distinguishable except on the last whorl; mouth rounded, oblique, inner lip 

 comparatively thin and in many cases not distinctly excavated. 



This neat and interesting shell is probably nearer C. sublceve than any of the others, but is readily 

 distinguished by its more slender as well as more rounded whorls. It is also a smaller shell. We have 

 before us five or six specimens of what appears to be a variety of C. gracik. They agree with the types, 

 with which they were also found, in every respect save that the revolving strias are much stronger and 

 readily apparent to the unassisted eye. Specimens of this kind may be known as var. striatulum. 



Formation and locality. Lorraine group, Cincinnati, Ohio, and vicinity; not uncommon. 

 Collection. E. O. Ulrich, (40 specimens.) 



