GASTROPODA. 1073 
Subulites sp. undet.] 
half, the columella relatively narrow; aperture comparatively wide, widest in the middle, the greatest 
width slightly exceeding a third of the length; outer lip sharp, nearly straight in the upper two-thirds, 
and strongly rounded, with also a moderate retral sweep, in the lower third; outer surface of shell per- 
fectly smooth in the material at hand. On a fragment of the body whorl, which seems to preserve only 
the inner layer of the shell, some eight or ten revolving brown bands are shown. 
This fine species is readily distinguished from most other species of the genus by its regularly taper- 
ing spire, and from others by the unusually abrupt contraction of the lower half of the body whorl. In 
the last feature, as well as in the resulting shape of the inner wall of the aperture, the species resembles 
Fusispira, particularly such species of that genus as F. planulata and F. nobilis. 
Formation and locality.—Stones River group, Cannon Falls, Minnesota; Murfreesboro, Tennessee; 
and High Bridge, Kentucky. Also near Ottawa, Canada, where it is said to occur in the Black River 
limestone. 
Collection.—H. O. Ulrich. 
SUBULITES, sp. undet. 
PLATE LXXXI, FIGS. 33, 34, 36 and 37. 
Compare Fusispiru? spicula SARDESON, 1892, Bull. Minn. Acad. Nat. Sci., vol. iii, p. 336, pl. v1, figs. 
10 and 11. g 
We have several specimens of a small Subulites agreeing with S. regularis in having a regularly taper- 
ing spire and rapidly contracting body whorl. The specimens consist of interior casts and testiferous 
fragments, and at first we thought they belonged to that widely distributed species. A careful compar- 
ison, however, shows that the whorls are almost perfectly flat in the spire instead of slightly convex, 
while the shell has a band at the suture that is not apparent in any examples of S. regularis. This banded 
suture allies the form with S. beloitensis and S. pergracilis, from which it is distinguished by the shape of 
its body whorl. The specimens in question are peculiar in one feature when compared with all true species 
of the genus, namely, the filling of the apical whorls is extremely limited, the casts of the interior being 
almost as acute at the apex as is the shell itself. 
Sardeson’s Fusispira? spicula, which came from the same bed, may be founded on an imperfect cast 
of this species, but as he describes the aperture as ‘‘subquadrate” and speaks of oblique lines of growth, 
we hesitate to say thatitis. Still, he may be mistaken. 
Formation and locality.—Shales of the Black River group, Minneapolis, St. Paul, Chatfield and Foun- 
tain, Minnesota. Also at Beloit, Wisconsin, and in the upper part of the Stones River group at High 
Bridge, Kentucky. 
Collections.—Geological and Natural History Survey of Minnesota; EB. O. Ulrich. 
Museum Register, No. 4050. 
Genus CYRTOSPIRA, n. gen. (Ulrich.) 
Like Subulites excepting (1) that the shells are shorter, especially in the spire, 
the length of the aperture generally exceeding half of the total hight of the shell; 
(2) that the shell is curved with one side of the outline straight, the other strongly 
arcuate, or the axis may be spirally turned so that the shell curves first in one 
direction and then in another; and (8) the truncation of the lower extremity of the 
aperture is not so apparent. Types, C. tortilis Ulrich and Subulites ventricosus Hall, 
We have separated this type of shells from Swubulites, to which it was hitherto 
referred, not only because it is strikingly different from the typical forms of that 
