THE NAUTILUS. 89 



Oreoiielix carixifera, n. sp. 



Tlje shell is lenticular, cjirinate, umbilicate, the widlh of umbilicus 

 between a fourth and a fiith tliat of the shell, whorls 4^, slowly- 

 increasing, the first 2^ strongly convex, obliquely striate, the strife 

 finer on the embryonic poition. Subsequent whorls are strongly 

 convex around the upper (inner) part, becoming concave near the 

 outer edge ; the striation is rougher, and some weak traces of sjiiral 

 striae appear in places. The hist whorl is noticeably concave above 

 and below the peripheral keel ; it descends very slightly or not at 

 all in front, and on the base there are very iriconspicuous, well 

 spaced spirals composed of granules. The oblique alt. and the 

 diameter of th.e apeture are equal, and there is a slight angle at the 

 termination of the keel. 



Alt. 0, diam. 9.4 mm.; width of umbilicus 2 mm.; oblique alt. and 

 diam. of aperture 4 mm. 



Garrison, Montana. Type and paratypes No. 99253 A. N. S. P. 



Oreohelix alpina Eliod, which comes from higii elevations (8,.')00— 

 9,000 ft.) in the Mission Mountiiins, is about tlie size of this snail, 

 but the whorls are less convex, the convexity of the later ones is 

 simple, while in carim'fcra there is a concavity above the periphery. 

 0. alpina has no spiral sculpture or granulation, and the keel is less 

 pronounced. I regard such similarity as exists as due to converg- 

 ence rather than to actual relationship. 0. Jiemphitll Nc. differs in 

 the sculpture and shape of the embryonic whorls. 



0. carinifera is one of the smallest Oreohelices, the dimensions 

 given above being those of the largest shell out of about 20 in the 

 two lots seen. A very similar small form was taken with 0. haydeni 

 in the Wasatch IMountains many years ago by the Wheeler Expe- 

 dition, but I think it will prove to be distinct. Its exact location in 

 thiit range is not known, and it was not among the forms taken by 

 Hemphill there. 



HOI.OSPIRA MESOLTA, n. Sp. 



The shnll is cylindric-fusiform, of a delicate pink-white tint, the 

 upper part wiiite with blue stains; dead shells while throughout. 

 Whorls 14, the first 2^ smooth, forming the mamillar embryonic 

 shell, the first whorl rapidly increasing, second swollen, next half 

 whorl very narrow. Subsequent whorls are nearly flat, rather finely 

 but strongly striate, regularly increasing to the 8th or 9ih whorl, 



