GASTROPODA. 1061 
Oyclonema humerosum. } 
CycLoNeMA HuMEROsUM, n. sp. (Ulrich.) 
PLATE LXXVIII, FIGS. 48—46. 
The average size in this species is somewhat greater than in either of the preceding forms, while the 
apical angle is generally wider and more constant, the majority of the specimens varying comparatively 
but little either way from 85°. The principal feature, however, is a strongly developed shoulder, giving a 
deeper suture than in any other species of the genus. This shoulder may be rounded or, especially in the 
Richmond group form, quite angular. In the latter the slope of the outer side of the last whorl is very 
often distinctly concave, and not infrequently undulated in the direction of the lines of growth. The 
same conditions occur less frequently though quite as well marked in the Lorraine form. The surface 
markings are fairly constant. About ten principal subequal carine occur on the outer slope of the body 
whorl, and about the same number of smaller ones on the periphery and base. The larger ones usually 
alternate with a much thinner set. 
Formation and locality.-Very abundant in the upper half of the Lorraine group at Cincinnati, and 
not rare at several horizons in the Richmond group, at Waynesville, Clarksville, Oxford and other locali- 
ties in Ohio. Also at Richmond, Versailles and other points in Indiana. 
Collection.—E. O. Ulrich. 
CYCLONEMA PYRAMIDATUM James. 
PLATE LXXVIII, FIGS. 33 and 34. 
Oyclonema pyramidata JAMES, 1874, Cin. Quar. Jour. Sci., vol. i., p. 152. 
In its typical form it is scarcely possible to confound this species with any other known, but there 
are varieties, one of which shows its derivation from C. mediale—the starting point for most of the Cin- 
cinnati species of Cyclonema—while another develops a shoulder at the top of the whorls, causing it to 
resemble C. humerosum. One of the best characters is the extension of the spiral striation over the entire 
base. In most of the other forms the spiral lines extend only about half across the base, the inner part 
having transverse striaw only. 
Formation and locality.—Lorraine group, Cincinnati and vicinity. 
Collection.—H, O. Ulrich. 
CYcLONEMA SIMULANS, n. sp. (Ulrich.) 
PLATE LXXVIII, FIG. 47. 
Of this species we have about fifty specimens. These show that the shell is of medium size, with a 
general form about intermediate between C. humerosum and C. mediale, though rather nearer the former, 
there being usually a small shoulder and a flattening or even a slight concavity of the outer slope of the 
last whorl. It is distinguished from both by its surface markings. These consist as usual of revolving 
and obliquely transverse lines, but the former are much weaker on the last two whorls and often quite 
obsolete near the mouth, while the latter are more distant exceptiug in the last third of the body whorl 
ofold examples. In the latter the mouth is sometimes irregularly expanded and thrown upward along the 
suture. 
Formation and locality—Upper division of the Lorraine group at Cincinnati, Ohio. 
Oollection.—E. O. Ulrich. 
