el LARAMIE FOSSILS. 85 
dered portion near the suture being at nearly right angles with the axis 
of the shell; spire comparatively small, and apparently only moderately 
elevated. Surface marked by the usual lines of growth, and upon the 
whole shouldered portion of the body volution, that is its distal portion, 
reaching to the suture, there are numerous small obliquely triangular 
papillz, which are arranged in oblique rows that coincide nearly with 
the lines of growth. 
Full length not accurately known, but the body volution of the type 
specimen was, when perfect, not less than 38 millimeters in length. — 
Only two fragments of this remarkable Physa have been discovered, 
but the characters shown by them, as recorded above and illustrated by 
figure 1 a on plate 22, are suéficient to distinguish it from any other 
species, either fossil or recent. When more perfect examples are found, 
it is not improbable they will shew characters that will require it to be 
separated, at least subgenerically, from the typical forms of Physa, as 
well as from other recognized sections of the genus. 
Position and locality.—Laramie Group; valley of Crow Creek, North- 
ern Colorado, about ten miles above the confluence of that creek with 
Platte River; where it was found associated with numerous other fresh- 
water mollusks, which are described in this article. 
PHYSA COPEI White. 
Plate 24, figs. 4 a and 6. 
Physa-copei White, 1877, Bull. U. 8. Geol. Sur. Terr., vol. iii, p. 602. 
Shell large, elongate subelliptical; volutions about four; body volu- 
tion large and moderately inflated; spire short, less than one-third the 
entire length of the shell; suture distinct but not deep; aperture elongate 
subovate in outline; callus of the inner lip moderately thick; surface 
marked only by the ordinary faint lines of growth common to the genus. 
Length, 50 millimeters; diameter of body volution, 25 millimeters. 
This fine Physa is the largest species known to me except P. pleuro- 
matis White, from the Wahsatch Group of Colorado, Wyoming, and 
Utah, some unusually large examples of which occur in the valley of 
White River, Northwestern Colorado. 
Position and locality.—The only known examples of this species were 
discovered by Prof. E. D. Cope in Laramie strata, near Cow Island, 
Upper Missouri River, Montana. 
PHYSA 2 
Plate 30, fig. 11 a. 
A single example, found in the strata of the Bear River Laramie series, 
is figured on plate 30. It is the only specimen belonging to the Physidé 
that has yet been found in that series, and is probably a new form, but 
it is too imperfect for specific description, especially as the species of all 
that family of shells have few salient characteristics. Perhaps it should 
be referred to Bulinus rather than to Physa. It is given a place in this 
article to show that the family is represented in the Bear River series, 
and to make this synopsis of the molluscan fauna of the Laramie Group 
as complete as possible. 
