88 BULLETIN 91, UNITED STATES NATIONAL MUSEUM. 



situated at the anterior extremity of the posterior fourth, between 

 the sutures, while the second is about as far posterior to the suture. 

 The posterior of these two grooves is bounded posteriorly by a slender 

 raised cord. In addition to this spiral sculpture the whorls are 

 marked by numerous fine spiral striations and decidedly retractive 

 lines of growth. The latter assume somewhat the appearance of feeble 

 riblets between the slender cord and the summit. Sutures strongly 

 constricted. Periphery of the last whorl well rounded. Base mod- 

 erately long, well rounded, with a very fine umbilical perforation; 

 marked by the continuation of the lines of growth and numerous fine 

 spiral striations, which are a little stronger than those on the spire. 

 Aperture broadly oval; posterior angle very obtuse; outer lip very 

 oblique, thin; inner lip very strongly curved and appressed to the 

 preceding turn; except the extreme anterior portion, which is free; 

 parietal wall glazed with a thin callus. 



The type, Cat. No. 250391, U.S.N.M., comes from Port Alfred (Coll. 

 No. 1264), has four postnuclear turns, and measures: Length, 1.5 mm.; 

 diameter, 0.7 mm. 



ODOSTOMIA (MENESTHO) RIFACA, new species. 

 Plate 18, fig. 3. 



Shell very elongate-ovate, milk white. Nuclear whorls well 

 rounded, smooth, immersed in the first of the succeeding turns, above 

 which the tilted edge of the last volution only projects. Postnuclear 

 whorls moderately rounded, having a strongly impressed spiral groove 

 a little below the summit, which causes this to appear as a well- 

 rounded spiral cord. The rest of the surface between the sutures is 

 marked by numerous very fine spiral lirations, and exceedingly fine 

 axial lines of growth. Sutures strongly constricted. Periphery of the 

 last whorl somewhat inflated, well rounded. Base slightly atten- 

 uated, very narrowly umbilicated, well rounded, marked by the con- 

 tinuation of the lines of growth and spiral lirations which equal those 

 of the spire in strength and spacing. Aperture irregularly ovate; 

 posterior angle acute; outer lip thin, oblique; inner lip decidedly 

 curved, reflected over and appressed to the preceding turn, the ex- 

 treme anterior tip only being free. A strong oblique fold marks the 

 insertion of the columella. Parietal wall glazed by a thin callus. 



The type, Cat. No. 250365, U.S.N.M., comes from Port Alfred (Coll. 

 No. 1238). It has five postnuclear whorls, and measures: Length, 

 1 .9 mm. ; diameter, 0.9 mm. 



ODOSTOMIA (MENESTHO) FICARA, new species. 

 Plate 16, fig. 1. 



Shell broadly elongate-conic, rather thick, bluish white, Nuclear 

 whorls small, deeply, obliquely immersed in the first of the postnuclear 

 turns, above which a part of the last two volutions project. Postnu- 



