MOLLUSES FROM MEXICAN BOUNDARY SURVEY— BALL, vol.xviii. 



HOLOSPIRA (METASTOMA) CROSSEI, new species. 



Sbell small, compact, twelve-wliorled, with two polished, smooth, 

 blunt unclear aud four increasing whorls, followed by a cylindrical 

 spire faintly transversely ribbed; suture distinct, base rounded with a 

 shallow umbilical chink ; aperture simple, slightly oblique, not projecting 

 beyond the periphery of the preceding whorl, the lip entire, slightly ex- 

 panded, without internal ridges. Height, 11 ; maximum diameter, 4 mm. 



Top of Hachita Grande Mountain, New Mexico. 



This resembles H. f/oldfussii., with an entirely diifereut interior, and 

 a less reflected and triangular peristome. 



HOLOSPIRA (METASTOMA) PILSBRYI, new species. 



Shell externally almost exactly like M. tryoni, rfeiffer, as figured by 

 Crosse and Fischer,' but that species has the internal characters ui)on 

 Avhich Strebel and Pteflfer based their section Bostrichocenlrum. The 

 present form has a height of 13 and a major diameter of 4 mm., aud 

 comprises two nuclear, six increasing, and six eqnal whorls. 



Puebla, ]\Iexico; Arizona, collected by Dr. Edward Palmer. 



HOLOSPIRA (DISTOMOSPIRA) BILAMELLATA, new species. 



Shell elongate, slender, blunt-tipped, with two smooth nuclear, six 

 increasing, aud nine subsequent equal whorls; sculi)ture of slightly 

 raised, distant, straight riblets, obsolete on the middle of the shell, 

 but strong on the last whorl, where they are crowded and rather irregu- 

 lar; umbilicus small, shallow; aperture as in H. crossei, but projecting 

 beyond the periphery of the preceding whorl. Height, 20.5; maximum 

 diameter, 5 mm. 



Hachita Grande Mountain, New Alexico. 



HOLOSPIRA (HAPLOSTEMMA) MEARNSII, new species. 



Shell small, compact, with two nuclear, seven increasing, and five 

 subsequent whorls; sculpture and aperture much as in H. crossei, the 

 base slightly appressed and the ribs closer and more i)rominent than 

 on the preceding whorls; umbilicus shallow; aperture projecting some- 

 what beyond the preceding whorl; the peristome hardly reflected, sub- 

 triangular, little thickened, and without folds internally; axis small, 

 subcylindric, with a strong, short lamella near the base in the penulti- 

 mate whorl; length, 14.5; major diameter, 4.5 mm. 



Hachita Grande ^Mountain, New JMexico. 



This resembles H. erossei exteriialiy, but is larger, with more pro- 

 jecting aperture. 



HOLOSPIRA (BOSTRICHOCENTRUM) VERACRUZIANA, new species. 



Shell closely resembling the enlarged tigure of i/. microsioma,- Pfeift'er, 

 but with a shorter apical cone aud larger aperture; it diifers also by hav- 



' Moll. Mexique. -Crosse aud Fischer, Moll. Mex., p. 337, l^\. xvii, figs. 9, 9a. 



