ART. 4 NEW UROCOPTID LAND SHELLS FROM MEXICO BARTSCH H 



This species strongly resembles Holospira {Holospira) topochi- 

 coana^ distinguished from it at a glance, however, by its minute 

 size. 



HOLOSPIRA (HOLOSPIRA) BACHIA, new species 



Plate 1, Fig. 10 



Shell small, rather stout, cylindro-conic, pale brown with white 

 ribs. Nuclear whorls 3, well rounded, forming an almost cylindrical 

 spire which is truncated at the apex, all but the last half turn marked 

 with fine granules onlj^; the last half whorl is marked by somewhat 

 irregular, poorly developed, axial riblets, which are much more dis- 

 tantly spaced than those on the postnuclear spire. The early whorls 

 of the postnuclear spire are moderately rounded and form a rather 

 long cone. They are marked by moderately, distantly spaced de- 

 cidedly retractively slanting, somewhat sinuous axial riblets which 

 increase in number and proximity as the whorls progress. On the 

 middle whorls they are about as wide as the spaces that separate 

 them and well developed. On the last turn they become less in 

 number, wider spaced and stronger. Suture well impressed. Pe- 

 riphery of the last whorl well rounded. Base very short, strongly 

 rounded, narrowly umbilicated, marked by the continuations of the 

 ribs which extend into the umbilical chink. The last whorl is solute 

 for a little distance. On this portion the axial riblets become much 

 enfeebled, very closely spaced and encircle the entire whorl. Be- 

 hind the posterior angle of the aperture is an obsolete keel. Aper- 

 ture subtriangular ; parietal wall somewhat curved, peristome ex- 

 panded and slightly reflected. The internal pillar is moderately 

 strong, hollow ; in the last turn it is much more slender than in those 

 preceding. The columellar fold begins on the last half of the last 

 turn and reaches its maximum development in the penultimate 

 whorl, where also the outcurved parietal fold and the basal fold, as 

 well as the rather slight labial fold, reach their maximum develop- 

 ment. None of these folds except the columellar twist extend pos- 

 terior to the penultimate turn. 



The type (Cat. No. 363152 U.S.N.M.) was collected by C. E. 

 Orcutt in river drift near the Rio Balsas Station, Guerrero, Mexico. 

 It has 13.1 whorls and measures — length, 12.7 mm. ; diameter, 4.3 mm. 

 Cat. No. 363153 U.S.N.M. contains three additional specimens which 

 yield the following measurements: 



