306 REPORT UNITED STATES GEOLOGICAL SURVEY. 



or six of the revolving' lines being seen on each volution of the spire) ; 

 -while only the revolving lines are continued below the middle of the 

 body-volution. 



"Length of a large specimen, 1 inch; breadth, 0.40 inch; angle of 

 spire, from 20° to 25°. 



" None of the specimens of this species yet seen are quite perfectly 

 preserved at the base of the aperture. Some of them look as if there 

 had been a slight angularity there, while others, differing in no other re- 

 spect, present appearances that leave room for doubt on this point. In 

 some of its characters, this shell reminds one of the fresh- water Gonio- 

 basis, to which I was at one time much inclined to refer it, and I am 

 hardly quite sure that it may not have to take the name Goniobasis coal- 

 villensis. Many authors refer very similar shells to Ghemnitzla, but it 

 has not so large and produced a body-volution and aperture as the forms 

 to which Mr. Conrad and Dr. Stoliczska proposed to apply that name. 

 If found in any of the Paleozoic rocks, most geologists would refer it to 

 Loxonema of Phillips. Whether or not the nucleus or apex of its spire 

 was covered, as hi the typical species of Turbonilla, I have been unable 

 to determine. It is a far larger shell, however, than the species upon 

 which that genus was founded. 



" Specifically, this species seems to be related to Turbonilla spillmani 

 Conrad (Journ. Acad. 1ST. S., vol. iv, new series, pi. 46, fig. 28), but its 

 vertical folds or costse are straighter, less crowded and less numerous, 

 while its revolving lines are smaller and more numerous. Its aperture 

 also certainly differs in being decidedly more angrdar above, and prob- 

 ably somewhat so below. It may likewise be compared with Scalaria 

 mathewsonii Gabb, from Cretaceous rocks of California, from which it 

 differs in having less convex volutions, or less rounded aperture, less 

 crowded vertical ridges, and more distinct and coarse revolving lines. 



" Locality and position. — Coalville, Utah ; from below the lowest heavy 

 hed of coal at that locality. Cretaceous." 



Genus PHYSA Draparnaud. 



Physa carletoni Meek. 



Plate 7, fig. 12 a. 



iPhysa carletoni Meek, 1873, An. Rep. U. S. Geol. Surv. Terr, for 1872, p. 508. 



No other example of this species, besides the single type-specimen 

 discovered by Mr. Meek, has ever been obtained. The following is his 

 description, and the figure on plate 7 was drawn from the type-specimen : 



"Shell rhombic-subovate, attaining a medium size; very thin; spire 

 short and small ; volutions about three, last one very large, or forming 

 near nine-tenths the entire bulk of the shell; aperture unknown; surface 

 showing rather obscure lines of growth. 



"Length, 0.56 inch; breadth, 0.35 inch. 



" The only specimen of this species I have seen is somewhat imperfect, 

 and so connected with a portion of the arenaceous matrix that its aper- 

 ture and columella cannot be seen. It seems to have most nearly resem- 

 bled such recent species as P. lordi Baud in general form. I should 

 not have attempted to name and characterize the species without seeing 

 the columella and aperture, had it not seemed desirable to call attention 

 to it as the first species of the genus hitherto found in the well-marked 

 Cretaceous strata of this country. 



u Locality and position. — Carleton's coal-mine, near Coalville, Utah, in 



