THE NAUTILUS. #9 



OREOIIEMX CARINIFERA, n. sp. 



Tlie shell is lenticular, carinatc, umbilicate, the width of umbilicus 

 between a fourth and a fifth that of the shell, whorls 4^, slowly 

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

 finer on the embryonic portion. 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 spiral 

 stria? appear in places. The last 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 inconspicuous, well 

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

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

 termination of the keel. 



Alt. 5, diam. 9.4 mm.; width of umbilicus 2 mm.; oblique alt. and 

 diarn. of aperture 4 mm. 



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



Oreohellx alpina Elrod, which comes from high elevations (8,500 

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

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

 simple, while in corintfcra 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. liemphilli 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. Itaydeni 

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

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

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

 Hemphill there. 



HOLOSPIRA MESOLIA, n. Sp. 



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

 upper part white with blue stains; dead shells white 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 fiat, rather finely 

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



