94 HOLOSPIRA. 



208, pi. 19, f. 10-13 (July, 1865). PPB., Monogr., vi, p. 389; 

 viii, p. 446. Holospira rcmondii Gabb, TRYON, A. J. C., iii, 

 p. 313, pi. 15, f. 32. FISCHER & CROSSE, Miss. Sclent. Mex., 

 Moll., i, p. 325, pi. 17, f. 2; Journ. de Conchyl., xviii, 1870, 

 p. 24. CROSSE, Journ. de Conchyl., xl, 1892, p. 262, pi. 5, 

 f. 8, 8 a. 



This species varies a good deal in size, and in the degree to 

 which the striation extends upon the lower whorls, but other- 

 wise is rather constant. The whorls of the cone project above 

 the sutures more or less in all the 8 specimens of the type lot, 

 but only slightly in some. The riblets are narrow and sim- 

 ple, and the enlarged first whorl is rounded and bulging, not 

 angular as in H. minima. It differs from H. crossei in the 

 flattening of the post-nepionic whorls of the cone and the 

 perforate base. H. arizonensis is slightly larger, with 

 smoother median whorls and less perfectly circular peri- 

 stome, and it differs in internal structure. 



19. H. MINIMA (v. Martens). PL 23, fig. 59; pi. 24, figs. 5-9. 



Shell rimate and perforate, cylindric, tapering in a rather 

 long cone above, thin, pale fleshy-brownish with lighter ribs, 

 the apex often darker. Whorls 11 to 12y 2 , the first 2 smooth, 

 strongly angular at the shoulder above, the upper and lateral 

 surfaces flattened (pi. 24, fig. 8) ; following whorls of the 

 cone strongly convex, angular in the middle, sculptured with 

 stout rounded ribs, which when worn are seen to be hollow. 

 Succeeding whorls are convex, sculptured with strong, regu- 

 lar ribs as wide as their intervals, and also hollow, in places 

 broken and showing the two lateral lamina? only. On the 

 last two or three whorls the ribs are somewhat smaller, and 

 on the last one they split or suddenly diminish on the base, 

 except upon the rounded part of the whorl behind the aper- 

 ture. Aperture subcircular, its plane not produced beyond 

 the general outline of the ventral side of the shell; peristome 

 white, expanded and reflected, continuous and free. Inter- 

 nal column smooth, widest above, gradually tapering down- 

 wards, a little exceeding 1 mm. in greatest calibre. 



Length 13-14, diam. 4.2 mm. ; whorls 12!/2- 



Length 13.5, diam. 4 mm. 



