GEOLOGICAL SURVEY OF THE TEERITOEIES. 601 



ever, and thus enabled me to see that it is denticulated, and in this 

 lespect differs from Neritina pisum, which seems to be entirely without 

 teeth. Further comparisons also show the two shells to differ in torn), 

 that under consideration having a more prominent spire and a more 

 globose outline, being less oblique. 



In size and general appearance it also closely resembles small exam- 

 ples of W^rifina compaeta, Forbes, from the Cretaceous rocks of India ; 

 but it is less oblique, or more globose in form, and has four denticles 

 instead of only three on its columella. It is possible I should call it 

 Nerita pisiformis, as the denticuiations of its columella are rather 

 strongly developed for a ]^eritina, in which genus the columella is usually 

 smooth, or only finely crenate. Its general aspect, however, is more like 

 species of the latter group. 



Locality and position. — Coalville, Utah, from the Cretaceous beds 

 below the heavy lower bed of coal mined there. 



AD3IETE? EHOMBOIDES, Meek. 



Shell rather small, rhombic-suboval, or short subfusiform, the length 

 being slightly more than twice the breadth at the widest part, which is 

 near the middle ; spire rather depressed-conical, subturreted ; volutions 

 five or six ; convex ; last one forming about three-fourths the entire bulk 

 of the shell, and more than half of its length, widest near its upper part, 

 and abruptly narrowed below so as to present an obliquely obovate 

 form ; suture rather deei) from the convexity of the volutions ; aperture 

 narrow, subangular above and narrowed below to a small notch at the 

 base of the truncated columella, which is provided with two small obscure 

 plaits or folds, the lower of which is formed by the twisted margin of the 

 truncated inner lip, while the other is placed a little farther up ; outer lip 

 sharp, with its margin slightly retreating above, and more prominent 

 below, or near the middle. Surface ornamented by distinct vertical folds, 

 that are usually well developed on the volutions of the spire, and around 

 the upper part of the bocly whorl, but become obsolete below ; moderately 

 distinct revolving lines also mark the lower part of the body volution, 

 but these appear to become obsolete on its upper part, and on those of 

 the spire, as specimens are usually found. 



Length, 0.37 inch; breadth, 0.21 inch ; angle of spire about 58°. 



1 am much perplexed in regard to the proper disposition to make of 

 this and the first two of the lollowing species. In some of their charac- 

 ters, they would seem to be related to certain types of the 3Iitrmce, such 

 as V'ul2)€CiiIa,'B\amYi\]e,{=Vulpecula,Kle\n ;) while in others they appear 

 to have afiinities to the Cancellariidw, being much like the genus Ad- 

 mete. Without being at all satisned, however, that they belong prop- 

 erly to the latter genus, I have concluded to refer them to it, provision- . 

 ally, for the present, until better specimens can be obtained for study 

 and comparison. My present impression is, that they will prove not to 

 belong properly to any of the established genera, when all their charac- 

 ters can be clearly made out. If it should be found desirable, however, 

 to establish a new group for their reception, I would propose for it the 

 name Admetopsis, from the resemblance of the shell to the typical forms 

 of the genus Admete. 



Locality and position. — Coalville, Utah. From Cretaceous beds be- 

 neath the lower heavy bed of coal at that place. 



Admete ? geegaeia, Meek. 



Shell small, oval, subfusiform ; spire moderately prominent, conical, 

 and apparently terminating in a pointed apex; volutions five or six, 



