1018 General Notes. 
We have in our cabinet many specimens of this species, all of 
the same form and size, and showing (with the single exception 
noted) the same surface marking. 
Position and locality: base of Rockford Shales, Rockford and 
Hackberry, Iowa. 
Cyclonema subcrenulata, n. sp.—Shell small, sub-turbonate ; 
spire depressed, sub-conical ; volutions three, increasing rapidly in 
size from the apex; those of the spire slightly convex, flattened ; 
last one large, equal to two-thirds the bulk of the entire shell, 
convex, flattened, or very broadly rounded; rounded at the peri- 
phery ; suture well defined; aperture oblong-ovate. Surface orna- 
mented by strong, sharply elevated, revolving ridges, which are 
distinctly crenated by the strong, slightly oblique lines of growth. 
these revolving lines, fifteen may be counted on the body 
volution in close proximity to the periphery, three of which are 
very minute, and implanted between the main ridges; these are 
rather short, as well as one of the main ones which joins the suture. 
On the upper portion of the body whorl, between the suture and 
the first revolving line, is a flattened or slightly concave space, 
which is marked by stronger and more oblique striæ than other . 
portions of the surface of the shell; on the whorl next above the 
body volution, four revolving lines may be counted. | 
This species seems to be somewhat closely related to C. crenulata 
of Meek (Geological Survey of Ohio, Paleontology, Vol. I., p. 213, 
Plate XIX., Fig. 2, a, d), but differs from it in its more strongly 
depressed form, less number of volutions, and slightly different 
form of the aperture; it also has a less number of revolving lines 
(three of which are minute and implanted), and a more profoun 
crenate character, as well as the distinct belt or flattened area 
occupying the upper part of the first volution. 
Dimensions: height, 114 mm. ; greatest width, 114 mm. i 
Position and locality: lower portion of Rockford Shales, Rock- 
ford, lowa.—Clement L. Webster. 
‘Unter Mitwirkung von Dr. A. Schenk. 
` 25 lieferung ; 154 Holzschnitten. Teleostei (finis) et Batrachia. 
