SOUTH AFRICAN MARINE MOLLUSKS. 115 



cord as that is from the one posterior to it; while the second, which 

 is considerably more slender, is a little posterior to the insertion of 

 the columella, the insertion of the columella being marked by a 

 strongly impressed groove. In addition to the above sculpture, 

 the entire base is marked by numerous, very slender, raised axial 

 threads and exceedingly fine, spiral, striations. Aperture subcir- 

 cular, decidedly channeled anteriorly; posterior angle obtuse; outer 

 lip thin, rendered sinuous by the spiral keels; columella short, strongly 

 curved and reflected over and appressed to the base ; parietal wall 

 covered with a thin callus. 



The type and three specimens of this species Cat. No. 187043, 

 U.S.N.M., come from Port Alfred (Coll. No. 581). The type has 

 10 postnuclear whorls and measures: Length, 7.6 mm.; diameter, 2.2 

 mm. The present species is much smaller than 8. alfredensis. In 

 coloration it is uniform chestnut brown, while S. alfredensis is macu- 

 lated. The axial sculpture consists of much finer and much more 

 numerous raised threads in africana than in alfredensis. The base 

 of the present species has two spiral cords, while in alfredensis we 

 have two incised lines only. 



Two additional lots from Port Alfred are in the collection of the 

 United States National Museum. Cat. No. 249686, 4 specimens 

 (Coll. No. 958). Cat. No. 249687, 4 specimens (Coll. No. 959.) 



SEILA SMITHI, new species. 

 Plate 12, fig. 7. 



Shell very slender, elongate-conic, light chestnut brown, the tip 

 a little lighter. First half of the nuclear turns smooth, the succeed- 

 ing two and a half, well rounded, marked by two spiral threads and 

 numerous, fine axial riblets, which are best expressed near the sum- 

 mit. Postnuclear whorls well rounded, marked by strong, some- 

 what flattened, equal and equally spaced, sublamellar spiral cords, 

 of which 5 occur between the sutures, the first being at the summit, 

 which it renders shouldered, and the last at the suture. The sulci, 

 between the cords, are a little wider than the cords and are crossed 

 by exceedingly numerous, very slender, slightly retractive axial 

 threads. Sutures strongly constricted. Periphery of the last 

 whorl marked by a strong spiral cord, which appears in the suture 

 of the preceding whorls and furnishes the fifth cord on the spire. 

 Base short, slightly concave on the posterior half, marked by very 

 slender spiral threads at the insertion of the columella and lines of 

 growth only. Aperture strongly channeled anteriorly; posterior 

 angle obtuse ; outer lip thin, rendered sinuous by the external sculp- 

 ture, which shows through the substance of the outer lip; columella 

 short, slightly curved, covered with a thin callus which extends up 

 on the parietal wall. 



