SOUTH AFRICAN MARINE MOLLUSKS. 27 



the rest of the turn between the sutures; of the latter 3 occur upon 

 the first to third, 4 upon the fourth, 7 upon the fifth and sixth, 1 1 upon 

 the next, and 13 on the last turn. The spaces between tho spiral 

 threads about equal the spiral threads in strength. The surfaco 

 between the spiral threads is covered with fine granulations on the 

 spire. The last whorl anterior to the periphery is marked by 27 spiral 

 cords, which are about equal and equally spaced, being only a trifle 

 stronger on the columella. Sutures well constricted; aperture with 

 a strong deep sinus at its posterior angle, which renders the outer lip, 

 anterior to this, decidedly claw-like; outer lip strongly reenforced 

 within by a callus which bears about 15 denticulations on the inner 

 surface. Columella and parietal wall glazed with a thin callus. 



The type, Cat. No. 210, U.S.N.M., was collected by William 

 Stimpson on the North Pacific Exploring Expedition at False Bay. 

 It has nine post-nuclear whorls and measures : Length, 15.3 mm. ; diam- 

 eter, 5.7 mm. Tho specimen was labeled Clathurella gracilis Montagu. 

 It differs from this in being uniformly smaller and having ever so 

 many more spiral cords. Named for Dr. Marcus Benjamin of the 

 United States National Museum. 



MANGILIA? CRASSILIRATA Smith. 



Cat. No. 187006, U.S.N.M., one specimen from Port Alfred (Coll. 

 No. 538). Cat. No. 250459, U.S.N.M., contains another specimen 

 from the same place (Coll. No. 1332). 



MANGILIA ARATA, new species. 



Plate 3, fig. 8. 



Shell vinaceous cinnamon. Nuclear whorls two, dextral, smooth, 

 well rounded. Post-nuclear whorls with the posterior third between the 

 sutures forming sloping shoulders, the rest well rounded, ornamented 

 by strong, rounded, almost vertical, axial ribs, which are about one-half 

 as wide as the intercostal spaces. Ten of these ribs occur upon the first 

 and second, 12 upon the third, and 14 upon the penultimate turn. In 

 addition to the ribs the whorls are marked by strongly raised, narrow, 

 spiral bands, of which, four, equally strong and equally spaced, divido 

 the space between the suture and the shoulder and three, that between 

 the shoulder and the summit; of these, two are close together, imme- 

 diately posterior to the shoulder, while the third divides the space 

 between them and the summit. Sutures somewhat constricted. 

 Periphery of the last whorl well rounded. Posterior half of base well 

 rounded and marked by the continuations of the axial ribs. Ante- 

 rior half produced. Entire base crossed by 20 raised spiral bands, 

 the posterior of which equals those on the spire, while thoso on the 

 anterior extremity appear as rounded lirations. Aperture of irregu- 

 lar outline, channel strong and deep, separated from the parietal wall 



