86 HOLOSPIRA. 



stoma), and the parietal portion is very little^ extended 

 beyond the periphery of the preceding whorl; the whorls of 

 the nucleus (l 1 /^) are smooth and polished, those of the 

 apical cone finely ribbed, those of the rest of the spire striate, 

 with a few coarse riblets just behind the peristome" (Dall). 



E. Mexico: Mizantla, province of Vera Cruz (three speci- 

 mens presented to the National Museum by the Mexican 

 Geographical Commission) . 



Holospira (Bostrichocentrum) veracruziana DALL, Proc. 

 U. S. Nat. Mus., xviii, p. 4 (1895) ; xix, p. 350 (1897). 



This species has a strong, short fold at the base of the axis 

 in the penultimate whorl, but no traces of any other laminae. 

 It is possible that the type of H. microstoma of Pfeiffer may 

 have the aperture abnormal and be identical with this spe- 

 cies, but in the uncertainty I have preferred to name the 

 latter (Dall). 



11. H. PILSBRYI Dall. PL 16, figs. 6, 7, 8, 9 ; pi. 23, fig. 76. - 



"Shell small, bluish or pinkish- white ; the nucleus darker, 

 2-whorled, smooth, not much projected, followed by 6 ob- 

 liquely striate, gradually increasing whorls which form a 

 bee-hive-shaped dome to the spire, after which follow 6 nearly 

 equal almost smooth whorls forming a nearly cylindrical 

 spire; the last whorl slightly smaller, the base and neck near 

 the aperture somewhat irregularly transversely wrinkled; 

 suture distinct, here and there edged by wrinkles transverse 

 to the whorl, but more or less obsolete, except near the suture ; 

 umbilical chink shallow, aperture a little oblique, subcir- 

 cular, with a faint angulation near the upper outer corner; 

 lip expanded, but hardly reflected; the peristome, viewed in 

 its own plane, does not project beyond the lines representing 

 the sides of the cylindrical part of the spire, but as the last 

 whorl is smaller than those preceding it, the peristome pro- 

 jects slightly from it; throat of the aperture whitish without 

 ridges; axis straight, slender, axial wall smooth. Length of 

 large specimen 13, diameter 4 mm., with 14 whorls; length 

 of short specimen 10.25, diameter 3.75 mm., with 12 whorls" 

 (Dall). 



