HOLOSPIRA. 95 



Length 11.7, diam. 4 mm. ; whorls 11%. 



State of Sonora, N.-W. Mexico : Cerro de la Campana, near 

 Hermosillo (A. Remond). 



C[ylindrella] pfeifferi GABB, Amer. Journ. of Conch., i, 

 p. 208. Holospira pfeifferi CROSSE & FISCHER, Journ. de 

 ConchyL, xviii, 1870, p. 13, pi. 5, f. 6-10 (jaw and teeth) ; 

 H. p. var 6, C. &. F., Miss. Scient. Mex., Moll., i, p. 324, pi. 17, 



1. CROSSE, J. de Conch., xl, 1892, p. 261, pi. 5, f. 7, 7 a. 

 . p. var. minor v. MARTENS, Biologia Centrali Americana, 

 oil., p. 280, and var. minima, p. 280, pi. 16, f. 18. H. 

 inima v. Mart., PILSBRY, Nautilus, xiv, p. 118. 

 This species is readily recognized by the angular upper 

 whorls and the very coarse though closely standing ribs, 

 which when broken down are seen to be hollow. I am quite 

 unable to see anything further than the usual individual 

 variation between the varieties minor and minima, recognized 

 by von Martens. In the specimens before me there are 32 to 

 34 ribs on the penultimate whorl. The original descriptions 

 of minima follow, and the original figure is copied on pi. 23, 

 fig. 60. 



* ' Subconic-turreted, densely, delicately lamellose-costate, 

 flesh-colored, the ribs white; aperture rounded; base perfo- 

 rated ; whorls 11, convex ; length ll 1 /^, greatest diam. 4, diam. 

 of penult, whorl 3% ; length of aperture 2%, width 2 y 2 mm. 

 "Length Iiy 2 mm. only, 4 in the largest diameter; aper- 

 ture 2y 2 mm.; whorls 11, distinctly convex; color reddish- 

 yellow, the costae white. Mexico, without nearer indication 

 of locality (coll. Patel)." 



Var. percostata Pils. PL 24, fig. 7. Whorls 11-11% ; ribs 

 more widely spaced, 23 to 26 on the penultimate whorl; 

 length 11.6 to 12.4, diam. 4 mm. N.-W. Mexico. 



(Group of H. fusca). 



20. H. FUSCA v. Martens. PL 25, figs. 8-14. 



Shell rather widely umbilicated, fusiform- cylindrical, 



I'ose-whorled, thin, very lightly obliquely striatulate, lilac- 

 rown. Whorls 19, the -first 2 subglobose, smooth, pale cor- 

 3ous (rarely blackish), following 7 whorls somewhat rapidly 



