140 BULIMULUS-ORTHOTOMIUM. 



the Bulirnuli of the region, they show the vertical riblets on 

 apical whorls, and a more sunken nucleus than in the Helix. No 

 single-banded Helix is known for 200 miles north of the locality of 

 this species." (Cooper*). 



Sierra San Lazaro, near Cape St. Lucas, Lower California (Eisen). 



Bulimulus decipiens COOPER, Proc. Cal. Acad. Sci. (2), v, p. 164 

 (June, 1895). Bulimulus (Orthotomium*) decipiens DALL, Proc. U. 

 S. Nat. Mus., xix, p. 358. 



" A third species was among those referred at first to B. pilula, 

 with some doubt, by Dr. Cooper in the series submitted to me. Un- 

 fortunately, the specimens, though living when obtained, are not 

 adult. They appear, however, to represent a very distinct species. 

 The shell is of pale, livid, pinkish-brown, with a peripheral, narrow, 

 pale-yellow band. The largest specimen has a Leptobyrsus nucleus 

 (not keeled) of 2 whorls, and about 2i rapidly enlarging later whorls. 



The suture is distinct, but not deep, the shell, when adult, is prob- 

 ably about the shape of sufflatus, but thinner ; the umbilicus is deep, 

 but very small, and almost hidden by the reflection of the pillar 

 lip ; the base is rounded ; the surface marked by inconspicuous in- 

 cremental lines and by spiral, microscopic but sharp, distant, 

 slightly elevated lines, between which are still finer spiral striations. 

 The general surface is not polished even when perfectly fresh, but 

 the wear on the fine elevated lines seems to polish them, so that 

 under a strong triplet they shine against the duller background of 

 the rest of the surface. This sculpture is very characteristic and 

 quite unlike that of any other Lower Californian species. The shell 

 above described measures 11*5 mill, high, of which the last whorl 

 stands for 10 mill., and 9'5 mill, in diameter. It was collected by 

 Eisen in the Sierra San Lazaro, near Cape St. Lucas, in September, 

 1894." (Da//)- 



B. LEVIS Ball. PI. 19, fig. 64. 



Shell thin, ovate-conic, narrowly umbilicate, white under a thin 

 olivaceous-yellow cuticle. Surface somewhat shining, with some- 

 what irregular, low growth-wrinkles but no spiral stride or granula- 

 tion. Whorls 5?, convex, the last more inflated than in B. xantu-n. 

 Aperture ovate, the peristome simple, unexpanded. Columella 

 straightened above, not folded ; parietal callus thin. 



Alt. 17, diam. 11'3, alt. of aperture 9 mill. 



Alt. 18, diam. 10'5 mill. 



Alt. 17, diam. 8'5 mill. 



