128 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxi. 



The unique type, Cat. No. 73987 U. S. N. M., was collected by 

 E. Lehnert in southwest Mexico. It has 17 whorls and measures: 

 Lenc^tli, 17.1 mm.; diameter of penultimate whorl, 3.0 mm.; diameter 

 of tenth whorl, 1.1 mm.; diameter of second whorl, 0.8 mm. 



HOLOSPIRA (HOLOSPIRA) PALM ERI, new species. 

 Plate IV, fig. 6. 



Shell small, slender, subcylindric, terminal cone tapering very gently; 

 light-brown to flesh color. Nuclear whorls two and one-half, very 

 minutely granulose. Succeeding whorls well rounded on the terminal 

 cone, almost flattened on the C3'lindrii'al portion of the spire, crossed 

 by many subequal and subequally spaced, regular, obliquely backward 

 slanting thread-like riblets. These riblets are less strongly developed 

 and more closel}^ spaced on the middle of the spire than on the two 

 ends. In the type 1 counted about 16 on the flfth, 80 upon the tenth, 

 and 5<) upon the penultimate whorl. Sutures well marked. Last 

 whorl prolonged, having the peripher}" and ])ase well rounded, both of 

 which are crossed by the ribs, which extend into the deep and broad 

 umbilical rimation. Base not perforate. The last two millimeters of 

 the last whorl are solute and built out. The outside of this part is 

 marked by strong continuous ribs, which form a series of concentric 

 circles about it. The parietal wall in the free part is decidedl}' pinched 

 at about one-third of the way to the left of its junction with the outer 

 wall, which renders the posterior lateral angle keeled. Junction of 

 parietal wall and columella well rounded. Outer wall of solute portion 

 somewhat concave in the middle. Aperture subtriangular, white at the 

 edge, grading to light brown within, peristome expanded but not re- 

 flected. Internal pillar slender, of uniform size, and hollow throughout, 

 marked by an inconspicuous, submedian twist which appears to extend 

 through the spire. In the penultimate whorl this twist is replaced by 

 a strong spiral lamella, which does not extend much either way beyond 

 the conlines of this turn. A strong spiral lamella hangs from the roof 

 in the penultimate and antepenultimate whorl; this is situated a little 

 lateral to the middle of the space between pillar and wall and extends 

 about one-third across the chamber. This lamella is strongly outward 

 curved in the antepenultimate whorl. It is marked by man}^ white 

 lines that alternate with hyaline ones. The lines run parallel with the 

 long axis of the lamella. The basal lamella is low, coextensive with 

 the parietal one and opposed to it. The fourth lamella is represented 

 by a low cord on the inside of the outer wall opposite the space between 

 the parietal and basal lamella in the antepenultimate whorl. None of 

 the lamellge extend to the last whorl. 



The collection contains 18 adults and 29 immature specimens and 

 fragments of this species. Cat. No. 100388, U.S.N.M., from Alvarez 

 Mountains, San Luis Potosi, Mexico, where they were collected by 



