88 THE CHICAGO ACADEMY OF SCIENCES. 



Type: U. S. Nat. Mus. no. 20055. 



Horizon : Atlantosaurus beds, Comanchean Period. 



Locality : Eight miles north of Canyon City, Fremont County, 

 Colorado. 



Remarks: "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 Pliysa 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. 



Limncea? accelerata White, Bull. U. S. Geol. Surv., no. 29, p. 21, pi. 4, figs. 

 12-15, 1886; Bull. U. S. Geol. Surv., no. 128, p. 71, 1895.— Boyle, 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). 



Type: 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 Limncea; 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 Limnaa. 

 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 



