46 C. A. White— Fresh-water and Land Mollusca. 
Planorbis proper is represented by P. aqualis White, in the 
Green River strata of Wyoming. Bathyomphalus has two rep- 
resentatives, namely, P. (B.) Revahensts “White, and P. (B) 
planoconvecus Meek & Hayden; both in the Laramie Group. 
Th er comes from Southera Utah, er the latter from 
Masha. Gyraulus — to have several representatives in 
both the Laramie and Green River strata; but G. militaris 
White, from strata probably of the Laramie period, is the only 
one Aes published. 
nsiderable number of species of the Physine are known in 
the Ay pean Wabhsatch and Green River groups, and the sub- 
family was well established before the first named period. It is 
an interesting fact, in confirmation of the latter statement, thata 
typical species of Physa, P. Carletoni Meek, has been found in est- 
uary strata at Coalville, Utah, which rest upon marine Cretaceous 
strata, and have more than 1 000 feet of similar marine Cretaceous 
strata resting upon them. This is the earliest Physa known in 
American strata. Physa pleromatis White, is a widely distribu- 
ted species in the Wahsatch group of Wyoming, Colorado and 
Utah, but true Physa is not common in the Laramie group, 
although that genus prevailed both before site after. In the 
last named group Bulinus is somewhat common; B. atavus 
White, and B. subelongatus Meck & Hayden, being published 
exam 
The Helicine appear to have been almost as diversely differ- 
—— pte the Laramie, Wabsatch and Green River 
ming, which crest at heey to the upper fie of the Laramie 
group, or the base of the Wahsatch, probably the former; and 
apparently also by an undescribed species in the Green River 
group of Wyoming. Triodopsis is represented by Helix Evan- 
stonensis White, which is associated with H. sepulta, just men- 
tioned. 
The Pupine have been recognized only in the Green River 
and Bridger groups; four species only having yet been discov- 
ered. The true character of the aperture has been ascertained 
only in one of these, and they are therefore assigned to the 
types mentioned, with some doubt. Their diverse forms, how- 
Bee res eee es aes he 
