26 BULLETIN 91, [TOTTED STATES NATIONAL MUSEUM. 



base, is marked by numerous, quite regular, closely spaced, axial 

 threads, which are best shown in the spaces between the spiral cords 

 and on the tabulated summit of the whorls. Aperture rather large, 

 scarcely channeled posteriorly; outer lip very thick, rendered den- 

 ticulate on the outside by the spiral cords; inner lip and parietal wall 

 glazed with a thin callus. 



Th a type, Cat. No. 250403, U.S.N.M., comes from Port Alfred 

 (Coll. No. 1336). It has four post-nuclear whorls and measures: 

 Length, 3.1 mm.; diameter, 1.5 mm. 



MANGILIA HELGA, new species. 



Plate 7, fig. 2. 



Shell wax yellow. Nuclear whorls one and a half, well rounded, 

 apparently smooth. Post-nuclear whorls strongly, tabulatedly 

 shouldered, marked by strong, spiral cords, of which 3 occur between 

 the angle of the shoulder and the suture on all the whorls; these are 

 a little wider than the spaces that separate them. On the middle of 

 the tabulated shoulder, a slender spiral cord begins on the first 

 whorJ, which increases in strength until it is about half as strong as 

 those anterior to it on the last turn. Sutures strongly constricted. 

 Periphery of the last whorl marked by a cord fully as strong as those 

 posterior to it. Base moderately prolonged, slightly rounded, 

 marked by three spiral cords which are almost as strong as those on 

 the spire and of about equal spacing with them. Aperture feebly 

 channeled posteriorly, decidedly so anteriorly; outer lip rendered 

 sinuous by the spiral cords; inner lip and parietal wall covered with 

 a thin callus. 



The type, Cat. No. 250470, U.S.N.M., comes from Port Alfred 

 (Coll. No. 1343). It has three and a half post-nuclear whorls and 

 measures: •Length, 3 mm.; diameter, 1.1 mm. 



MANGILIA BENJAMINI, new species. 

 Plate; 7, fig. 5. 



Shell elongate-conic, flesh colored. Nuclear whorls, more than one, 

 smooth. Post-nuclear whorls strongly rounded; the sinus falling at 

 the summit where the whorls are somewhat contracted; surface of 

 the post-nuclear whorls marked with strong, rounded, protracted 

 axial ribs, which begin practically anterior to the sinus and extend 

 strongly to the periphery; they are scarcely denned anterior to this 

 on the las) whorl. Of these ribs 10 occur upon the first to fourth, 12 

 upon the fifth to seventh, and 14 upon the penultimate turn. The 

 axial ribs are about as wide as the spaces that separate them. In 

 addition to these axial ribs the whorls are marked by numerous 

 slender spiral threads, of which about 5 occur in the area of the 

 sinus on the last three turns. These are finer than those which cover 



