88 THE CHICAGO ACADEMY OF SCIENCES. 
Type: U.S. Nat. Mus. no. 20055. 
Horizon: Atlantosaurus beds, Comanchean Period. 
Locauity: Eight miles north of Canyon City, Fremont County, 
Colorado. 
RemMaArRKs: “This species, although small, is somewhat larger than 
the one last described, and it is also more robust than is usual with 
species of this genus, approaching Physa in that respect” (White). 
Consortis resembles the short-spired forms of Galba catascopium 
more than any other recent species. The shell has a superficial resem- 
blance to young examples of Radix auricularia, but differs in the form 
of the inner lip and columella. No perfect specimens have been found 
and the form of the outer lip is, therefore, unknown. No undoubted 
representative of Radix, either recent or fossil, has been found in 
America. 
Galba accelerata (White). Plate XVI, figures 5-8. 
Limnea? accelerata Wuite, Bull. U. S. Geol. Surv., no. 29, p. 21, pl. 4, figs. 
12-15, 1886; Bull. U. S. Geol. Surv.,; no. 128, p. 71, 1895—Boyte, Bull. U. S. 
Geol. Surv., no. 102, p. 167, 1893—ScHUCHERT, Bull. U. S. Nat. Mus., 53, i, 
p. 355, 1905——Darton, Bull. Geol. Soc. Amer., XIX, p. 446, 1908—Darton & 
SIEBENTHAL, Bull. U. S. Geol. Surv., 364, p. 30, 1909. 
“SHELL elongate ovoid; aperture a little shorter than the spire in 
adult shells; sides of the spire convex, rounding in more or less 
abruptly toward the apex, but when perfect the extreme apex is small 
and prominent; volutions convex, seven or eight in number when the 
shells have reached adult size, those near the apex being narrower and 
more transverse than the last two, during the production of which the 
axial extension of the shell was proportionately more rapid than in 
its earlier stages. Surface plain, being marked only by fine lines of 
growth. 
“Length, 20 millimeters; diameter of the last volution, 7 milli- 
meters” (White). 
Tyre: U.S. Nat. Mus. no. 20056. 
Horizon: Atlantosaurus beds, Comanchean Period. 
LocaLity: Eight miles north of Canyon City, Fremont County, 
Colorado; Como Ridge, Albany County, Wyoming. 
REMARKS: “It is apparent at a glance that this shell is not a 
typical Limnea; but after careful comparison with several other generic 
forms which have a similar facies I have not been able to refer it to 
them satisfactorily, and I therefore place it provisionally under Limnea. 
Some of the specimens show a considerable deposit of callus upon the 
inner lip, in which case the flexure of the lower portion of the colu- 
mella has something of the appearance of a fold such as some of the 
