1060 THE PALEONTOLOGY OF MINNESOTA. 



[Cyclonema Inflatum. 



which occur quite generally in Conrad's species. The suture is comparatively shallow. There are two 

 common varieties, one having three widely separated strong carinaa on the upper slope followed below by 

 smaller and gradually decreasing and crowding ridges or lines, the last occurring usually about the middle 

 of the base. Much thinner revolving lines generally occur between the larger. In the other variety ( see 

 figures ) the revolving ridges are more equal in size and distribution, and at least three more in number. 

 On the body whorl they number between fifteen and twenty, but not more than eight or ten of these show 

 on the next whorl above, while in the first variety but four are shown. The apical angle for the whole 

 shell varies greatly but always is narrower for the upper turns than it is for the last two or three. 



The strongly carinated variety resembles and probably was derived from C. varicosum Hall, but its 

 whorls are less convex and the upper part of the spire more slender, the entire shell of C. mediate consisting 

 of six or seven whorls, while C. varicosum probably never has more than five volutions. The columellar 

 lip also is straighter and both the revolving and transverse ridges and lines stronger in Hall's species. 



Formation and locality. This is an abundant and highly characteristic fossil of the lower half of the 

 Lorraine group in Ohio, Kentucky and Indiana. We have over two hundred specimens from the vicinity 

 of Cincinnati. 



Colkction. E. O. Ulrich. 



CYCLONEMA INFLATUM, n. sp. (Ulrich.) 



PLATfi LXXVIII. FIGS. 31 and 32. 



Shell of medium size, consisting, as usually found, of about four rounded whorls; with the apex 

 entire there are in all about seven whorls, the first four forming a narrow truncated cone, the two turns 

 at the apex being coiled in' a very wide angle; succeeding whorls spreading more rapidly, the angle 

 increasing in some extreme cases from 40 to 90; mouth rounded, quadrangular; surface strongly carinated 

 spirally, the carinae on the upper half of the whorls more distant than those on the lower, fifteen to twenty 

 in all on the body whorl. 



This species agrees closely in its surface markings with certain varieties of C. mediate; and perhaps 

 it also should be regarded as an extreme variety of that species. Generally it is readily distinguished by 

 its more convex whorls. 



formation and locality. Lower half of the Lorraine group Cincinnati and vicinitv 

 Colkction. E. O. Ulrich. (25 specimens.) 



CYCLONEMA VARICOSUM Hall. 



PLATE LXXVIII, FIGS. 27 and 28. 



Cyclonema (ventricosa in error for) varicosa HALL, 1870, Twenty-fourth Eep. N. Y. St. Mus. Nat. Hist., 



pi. vm. (Not defined.) 

 Cyclonema cincinnatiense MILLEH, 1882, Jour. Cin. Soc. Nat. Hist., vol. v, p. 230. 



Though closely related to C. mediate this shell is still easily distinguished by its straighter columel- 

 lap lip, fewer, stronger and sharper revolving and tranverse surface markings, deeper suture and more 

 convex whorls. The revolving ridges, especially those on the outer side of the whorls, are very strong and 

 prominent. Between each two there are usually several much thinner lines. Of the principal carinte the 

 body whorl has only nine.or ten, and of these only five or six are shown on the whorls above the last. 



Cyclonema cincinnatiense Miller is founded on email examples of this species obtained from the upper 

 beds of the Trenton group opposite the city of Cincinnati. 



Formation and locality Two imperfect specimens of this species were collected at Wykoff, Minne- 

 sota, where they were found in the upper part of the Fusispira bed. The original type was obtained from 

 the upper part of the Trenton group at Nashville, Tennessee. The species occupies the same position at 

 Colby, Kentucky, and in the vicinity of Cincinnati. 



Collection. E. O. Ulrich. (15 specimens.) 



