478 PROCEEDINGS OF THE ACADEMY OF [1897* 



Aperture oblique, roundly cresceutic, the width hardly exceeding 

 the height ; peristome thin, but very slightly expanded below, the 

 columellar margin expanded, slightly recurved, but little impinging 

 upon the umbilicus; 



Alt. 15, greater diam. 24, lesser 21*7 mm.; width of aperture 11, 

 height 11 mm. 



Brazil. 



Smoother above than any of the other large species. Perhaps 

 Pfeiffer's "Streptazis Candida var.," Chemnitz, edit. 2, Helix, PI. 103, 

 f. 29, 30, is this species ; but in fig. 29 the basal lip is less deeply 

 rounded than in typical helios. 



S. tumulus n. sp. 



Shell subglobose-depressed, umbilicate, the umbilicus deeply pen- 

 etrating, cylindrical or well-like, one-seventh the diameter of shell ; 

 solid; white or yellowish with brilliant gloss, the upper surface 

 sculptured with smooth, regular, slightly arcuate, rounded costulse, 

 wider than their intervals, and on the last whorl about 2? in the 

 space of a millimeter; becoming obsolete at the periphery, the base 

 being smooth with the luster of varnish. Spire low dome-shaped, 

 the earlier whorls slightly conic. Whorls 7, very slowly increasing, 

 the last scarcely wider than the penultimate (viewed from above),, 

 rounded at periphery and convex beneath, showing two slight vari- 

 ceal ridges marking former peristome positions. Aperture oblique, 

 rotund-crescentic, mainly basal, but little wider than high ; peri- 

 stome not expanded above, becoming slightly so at base, and ex- 

 panded and slightly recurved at the columellar margin, where it is 

 dilated somewhat and impinges upon the umbilicus. 



Alt. 18, greatest diam. 25, lesser 23 mm. ; width of aperture 12, 

 height 1 T7 mm. 



Brazil. 



The outlines of the spire are more convex than in S. spixiarais 

 Pfr., the whorls more compactly coiled, the last conspicuously nar- 

 rower. The aperture is rounder and more basal, and the umbilicus 

 decidedly smaller. Compared with S. regius Lobbecke, this species 

 is less elevated with decidedly narrow umbilicus. 



S. capillosus n. sp. 



Shell closely resembling S. Spixianus Pfr. in general contour, 

 openly umbilicate, the umbilicus from one-sixth to one-fifth the 

 diam. of shell ; moderately solid ; grayish-white or yellowish. Sur- 



