SOUTH AFRICAN MARINE MOLLUSKS. 167 



Family VITRINELLIDAE. 



Genus VITRINELLA C. B. Adams. 



VITRINELLA RIFACA, new species. 



Plate 37, figs. 1, 2, 3. 



Shell small, planorboid, cream yellow. Nuclear whorls two, well 

 rounded, smooth. Postnuclear whorls one and one-fifth, well rounded, 

 marked by lines of growth only. Sutures strongly impressed. Pe- 

 riphery of the last whorl well rounded. Base very broadly umbili- 

 cated, showing all the whorls within, the individual whorls well 

 rounded, smooth excepting the lines of growth. Aperture slightly 

 oblique, subcircular, thin at the edge, thickened only at the parietal 

 wall. 



The type, Cat. No. 249775, U.S.N.M., comes from Port Alfred 

 (Coll. No. 1047). It measures: Altitude, 0.5 mm.; greater diameter, 

 1.8 mm. 



VITRINELLA CIFARA, new species. 



Plate 37, figs. 7, 8, 9. 



Shell small, depressed helicoid, translucent. Nuclear whorls a 

 little more than two, well rounded, marked by fine lines of growth 

 only. Postnuclear whorls well rounded, marked by strong lines of 

 growth. Suture strongly impressed, almost channeled. Periphery 

 strongly rounded. Base openly umbilicated, showing all the whorls 

 within, which are well rounded and marked by lines of growth only. 

 Aperture oblique, oval; outer lip thin; inner lip strongly curved; 

 parietal wall covered with a thick callus which renders the peritreme 

 complete. 



The type, Cat. No. 249767, U.S.N.M., comes from Port Alfred 

 (Coll. No. 1039). It has a little more than one postnuclear turn, 

 and measures: Altitude, 0.5 mm.; greater diameter, 1.4 mm. 



This species closely resembles the last, but is much more elevated, 

 less widely umbilicated, and the whorls are bent more downward 

 than in the preceding species. 



VITRINELLA FICARA, new species. 

 Plate 34, figs. 1, 2, 3. 



Shell rather large, planorboid, yellowish. Nuclear whorls one 

 and one-half, very large, well rounded, smooth. Succeeding turns 

 well rounded, marked by numerous ver} r fine thread-like ribs, the 

 spaces between which are marked by numerous fine spiral striations. 

 Sutures strongly constricted. Periphery strongly rounded. Base 

 openly umbilicated, showing all the whorls within, which are less 

 rounded and marked like the spire. Aperture oblique, subcircular. 



The type, Cat. No. 349775a, U.S.N.M., comes from Port Alfred 

 (Coll. No. 1047a). It has a little more than one and one-half post- 



