SOUTH AFRICAN MARINE MOLLUSKS. 121 



Family LITIOPIDAE. 

 Genus ALABA A. Adams. 



ALABA PINNAE Krauss. 



There are three lots of this species in the United States National 

 Museum, all from Port Alfred. Cat. No. 186813, seven specimens 

 Coll. No. 179). Cat. No. 187052, eight specimens (Coll. No. 590). 

 Cat. No. 250413, one specimen (Coll. No. 1286). 



Genus ALABINA Dall. 



ALABINA ALFREDENSIS, new species. 



Plate 5, fig. 7. 



Shell elongate-conic, white. Nuclear whorls about two and one- 

 half, smooth, well rounded. Postnu clear whorls with a strong 

 sloping shoulder which extends over the posterior half of the whorls 

 and is bounded anteriorly by a median spiral keel. A second keel, a 

 little less strong than the median, occupies the space halfway between 

 the suture and the median keel. In addition to the above sculpture 

 the whorls are marked on the anterior half, between the sutures, by 

 ill-defined axial ribs which lend the two keels a slightly tuberculated 

 appearance. About twelve of these feeble tubercles occur upon the 

 antipenultimate whorls. Periphery and base of the last whorl well 

 rounded, the latter smooth, excepting feeble lines of growth. Aper- 

 ture moderately large; outer lip thin; columella slightly curved and 

 feebly revolute; parietal wall glazed with a thin callus. 



The type, Cat. No. 187053, U.S.N.M., comes from Port Alfred (Coll. 

 No. 591). It has nine and one-half post-nuclear whorls, and meas- 

 ures: Length, 3.2 mm.; diameter, 1.2 mm. 



ALABINA AFRICANA, new species. 

 Plate 12, fig. 1. 



Shell small, elongate-conic, semitransparent, white. Nuclear 

 whorls one and a half, well rounded, separated by a strongly con- 

 stricted suture, and marked by four strong, equal and equally spaced, 

 spiral keels. Postnuclear whorls well rounded, marked by almost 

 vertical, well rounded, quite regular, axial ribs, of winch 14 occur upon 

 the first and second, 16 upon the third and fourth, 18 upon the fifth 

 and the penultimate turn. In addition to the axial ribs, the whorls 

 are marked by two spiral cords a little anterior and posterior to the 

 middle of the space between the sutures. The junction of the axial 

 ribs and the spiral cords forms tubercles, which are truncated poste- 

 riorly and slope gently anteriorly, while the spaces inclosed between 

 them appear as well impressed pits. Sutures strongly constricted. 

 Periphery of the last whorl marked by a strong, smooth, spiral cord. 

 Base short, slightly concave, smooth. Aperture subcircular; pos- 



