AST. 6 A NEW WEST INDIAN MOLLUSK FAUNTJLA BAETSCH 9 



cidedly near the aperture almost to the middle of the base. Aper- 

 ture decidedly oblique, oval. Outer lip thin at the edge, scarcely 

 expanded; the inner and basal lip are reflected over the base as a 

 thick callus. The basal lip bears a strong denticle about one-third 

 of the distance between the columella and the outer lip. Parietal 

 wall is covered by a thin callus. 



Type.— The type, U.S.N.M. No. 403912, measures : Height, 8.9 mm ; 

 greater diameter, 12.2 mm; lesser diametei-, 10.4 mm. 



Remarks. — U.S.N.M. No. 403900 contains four additional speci- 

 mens. 



THYSANOPHORA BEATENSIS, new species 



Plate 1, Figures 1, 2, 3 



Shell minute, depressed helicoid, semitranslucent, pale straw-col- 

 ored. Nuclear whorls 2, well rounded, polished, marked b}'^ exceed- 

 ingly fine incremental lines and exceedingly fine closely approximated 

 microscopic spiral striations only. Postnuclear whorls well rounded, 

 showing fine lines of growth and exceedingly fine microscopic spiral 

 striations. Suture well impressed. Periphery of the last whorl 

 well rounded. Base well rounded, openly umbilicated, the umbilicus 

 about one-fifth the width of the diameter of the shell. The aperture 

 is oblique; the outer lip does not descend at its termination. Col- 

 umella short and gently curved; the peristome not expanded. 



Type. — U.S.N.M. No. 403917 has 4.3 whorls, and measures : Height, 

 2 mm; greater diameter, 3.1 mm; lesser diameter, 3 mm. 



Remarks. — U.S.N.M. No. 403890 contains about 70 topotypes. 



THYSANOPHORA ALTA, new species 



Plate 1, Figxjbes 4, 5, 6 



Shell minute, helicoid, decidedly elevated, pale straw-colored. 

 Nuclear whorls 1.5, strongly rounded, smooth excepting fine incre- 

 mental lines and microscopic granules. Postnuclear whorls 2.7, 

 inflated, strongly rounded, separated hy a low impressed suture and 

 marked by incremental lines, the surface being rendered slightly 

 roughened by the attachment of foreign matter. Periphery inflated, 

 strongly rounded. Base well rounded, openly umbilicated, the um- 

 bilicus about one-sixth of the width of the diameter of the shell. 

 Aperture oblique, and broadly oval; outer lip thin at the edge. 

 Columella moderately long, curved. Parietal wall covered with a 

 thin callus. 



ry/?e.— The type, U.S.N.M. No. 403918, measures : Height, 2.3 mm ; 

 diameter, 3 mm. 



Remarks. — This is a member of the Boothiana group. 



