92 HOLOSPIRA. 



ate, the next whorl the widest of all and smooth, the remain- 

 der very rapidly decreasing in diameter towards the attenu- 

 ated base; last whorl with about 10 elevated ribs, not 

 carinated below, and appressed against the shell so as hardly 

 to be rimate, until extended beyond it, and ending in a con- 

 tinuous peritreme expanded around the subquadrate aper- 

 ture. Length 29, greatest diam. 7 mm. (Binn.) 



Cienga Grande, State of Coahuila, Mexico (coll. Smith- 

 sonian Inst.). 



Cylindrella coahuilensis W. G. B., Amer. Journ. of Conch., 

 i, p. 50, pi. 7, f. 4, 5 (Feb. 15, 1865). PFR., Monogr., viii, p. 

 445. Gongylostoma coahuilensis Binn., TRYON, Amer. Journ. 

 of Conch., iii, p. 312, pi. 15, f. 29. Holospira c., FISCH. & 

 CROSSE, Miss. Scient. Mex., Moll., i, p. 334. CROSSE, Journ. 

 de Conehyl., xl, 1892, p. 274, pi. 5, f. 1, 1 a. Metastoma c., 

 DALL., Proc. U. S. Nat. Mus., xix, p. 351. 



Crosse has figured a specimen somewhat broken measuring, 

 length 25, diam. 6 mm. (figs. 68, 69). Figures 66, 67 are 

 copied from Binney's original illustration. 



(Group of H. remondii). 

 17. H. CROSSEI Dall. PI. 23, figs. 64, 65, 75. 



Shell small, compact, 12-whorled, of a brownish-gray color; 

 nuclear whorls 2, smooth, polished, apically blunt, succeeding 

 4 gradually and evenly increasing, after which the shell is 

 cylindrical; sculpture of pretty even, slightly oblique, 

 rounded riblets, extending from suture to suture and sepa- 

 rated by interspaces twice as wide as the ribs ; suture distinct ; 

 base rounded, with a shallow umbilical chink; aperture sim- 

 ple, slightly oblique, not projecting beyond the periphery of 

 the preceding whorl, the lip slightly expanded in front of a 

 faint constriction, the opening subcircular without internal 

 ridges, the outer anterior part obtusely angular; axis small, 

 regularly increasing to the last whorl, not inflated. Length 

 of shell 11, maximum diameter 4 mm. (Dall.) 



New Mexico: Top of Hachita Grande Mountain, Grant 

 county (Dr. Mearns) ; no. 129989, U. S. N. M. 



Holospira (Metastoma} crossei DALL, Proc. U. S. Nat. Mus., 

 xviii, p. 3 (1895) ; xix, p. 348, pi. 31, f. 2 (1897). 



