BULIMULUS-SONORINA. 161 



aperture large, the lips approximated behind, the reflection wide 

 and greatly recurved, of a livid waxen passing into white at the 

 margin ; body moderately callous, pillar straight with an obscure 

 fold visible at the aperture, internally with a large, thick sublingui- 

 form lamina ; surface of the shell like that of B. excelsus, but more 

 polished. Length of shell, 36'5 ; of last whorl, 25; of aperture, in- 

 cluding the lip, 20 ; maximum of diameter of shell, 20 ; of aperture, 

 15 mill. (Datt). 



Espirito Santo Island, Gulf of California (Belding). 



Bulimulus (Leptobyrsus) veseyianus DALL, Proc. U. S. Nat. Mus., 

 xvi, 1893. p. 645, pi. 72, f. 4, 5. 



This species is named in honor of Mr. J. Xantus de Vesey, to 

 whom we owe much of our knowledge of the fauna of Lower Cali- 

 fornia. It is recognizable by its short, stout shape, widely reflected 

 recurved peristome, very narrow space between the commissures of 

 the lips and body, and large subtriangular lamina. Five specimens, 

 all very uniform, were collected by Mr. Belding some ten years ago 

 (Dalt). 



B. LAPIDIVAGUS Mabille. 



Shell covered perforate, pupiform, rather thick, a little opaque, 

 destitute of cuticle and color; striate, the striae delicate, undulating, 

 rather regular. Whorls 7, a little convex, rapidly and regularly 

 increasing, separated by impressed sutures, the last whorl large, in- 

 flated, a little tapering below, about equal to three-sixths the length 

 of shell. Aperture a trifle oblique, ovate-subrotund ; peristome 

 widely expressed and reflexed, a little thickened, the margins ap- 

 proximating and joined by a very thin callus; outer margin well- 

 arched, columellar margin broadly dilated, covering the perforation ; 

 columella obliquely straight, thickened, passing into a twisted median 

 profoundly entering lamina. Alt. 40-43, greatest diam. 16-18 

 mill. ; aperture with peristome 21 mill, long, 17 wide (Mabille). 



Sierra de Cacachila, south of La Paz (Diguet). 



Bulimulus (Leptobyrsus) lapidivagus MABILLE, Bull. Soc. Philo- 

 math, de Paris (8), vii, p. 66, 1895. 



B. DENTIFER Mabille. 



Shell oblong, turriculate, ri mate-perforate, destitute of cuticle, 

 subopaque, solid, striate ; ornamented with minute longitudinal rib. 

 let-like striaB and spiral lines visible only under a lens ; apex rather 

 11 



