AMERICAN SPECIES OF VERTIGO. 135 



California: San Bernardino Mts., at Bluff Lake, 7,550 ft., 

 type loc. ; also Bluff Lake cienaga, in the cienaga just north, 

 and along the "New England Trail," 7500 ft. ; cienaga west of 

 Green Valley, 6900 ft., S. S. Berry. 



Vertigo occidentalis STERKI, Nautilus xxi, Dec., 1907, p. 90. 

 -PILSBRY, Nautilus xxi, Apr., 1908, p. 133, pi. 11, f. 5.- 

 BERRY, Nautilus xxiii, Nov., 1909, p. 75. 



The original description was from a single specimen, which 

 seems not quite mature, drawn in page 124, fig. 7 (no. 1860 

 coll. Berry). An older shell from the type locality, pi. 10, 

 fig. 11, has the teeth somewhat stronger, particularly the colu- 

 mellar lamella, which is a very low nodule in the type specimen. 



The more conic shape and more distinctly perforate base, 

 as well as the smaller teeth, distinguish occidentalis from 

 V. m. parietalis; the columellar lamella, too, appears to be a 

 little more immersed than in parietalis, and there is no crest 

 behind the peristome. 



I have not been able to satisfy myself about the status of this 

 snail. On account of the ovate, tapering shape, I am dis- 

 posed to give it specific rank, as Dr. Sterki has done ; yet there 

 appear to be some equivocal forms connecting with V. m. 

 parietalis, which influenced me to use the subspecific form. 

 No doubt the examination of large series from the original 

 locality will clear up this uncertainty either demonstrating 

 intergradation or a constant difference. 



26. VERTIGO HOPPII (Moller). Page 124, figs. 6, 6a. 



"Shell dextral, cylindric, obtuse, smooth; columella two- 

 toothed. Length 1.2 lines" (Moller). 



"Shell subperforate, cylindric-ovate, thin, very delicately 

 striatulate, with a rather glossy, pellucid brown (often white) 

 epidermis; spire convexly-coiiic. Whorls 5 or 7%, convex, 

 suture deep, ascending in front; columella with an obtuse 

 fold ; parietal wall having a compressed, almost median fold ; 

 aperture subtriangular, the peristome a little reflected, the 

 outer lip moderately arched, with a very obsolete denticle in 

 front of the middle. Length 2%, diam. 1 mm." (Moerch). 



Greenland: Nisik, in the Kusukfjord; Igaliko; different 



