SOUTH AFRICAN MARINE MOLLUSKS. 19 



CLAVATULA HALIPLEX, new species. 

 Plate 2, fig. 3. 



Shell robust, fusiform. Whorls sloping from the summit and the 

 periphery to a depressed line midway between the sutures. The 

 portion posterior to the median line is smooth excepting the strongly 

 retractive lines of growth and spiral striations. The portion anterior 

 to it is marked by distant, low, broad, feebly developed axial ribs, 

 which appear as nodules above the sulcus. On this part the incre- 

 mental lines are decidedly protractive. Sutures well marked. Pos- 

 terior portion of base well rounded, anterior part produced rendering 

 the left outline of the whorl concave, marked by feeble extensions 

 of the ribs which disappear shortly after passing over the periphery. 

 Entire surface of spire and base marked by very fine, closely spaced 

 wavy spiral striations. Aperture of irregular outline; posterior angle 

 acute; sinus moderately deep, in the middle between the periphery 

 and summit; columella stout, somewhat sinuous and twisted, cov- 

 ered by a thin callus, which also extends over the parietal wall. 

 Color uniformly cream yellow. In some of the young specimens the 

 space between the sulcus and summit and tip of base are white, the 

 rest light brown. 



The type and one other individual, Cat. No. 186992, U.S.N.M., 

 come from Port Alfred (Coll. No. 524). The type has lost its early 

 whorls, the seven remaining measure: Length, 29.5 mm.; diameter, 

 11.6 mm. Cat. No. 186997, U.S.N.M., contains three young indi- 

 viduals from the same locality (Coll. No. 529). 



CLAVATULA HALISTREPTA, new species. 

 Plate 2, fig. 5. 



Shell fusiform. Whorls marked by a narrow, obscurely nodulous 

 spiral keel at the summit, which is followed by a depressed spiral 

 sulcus that equals the keel in width, the two comprising the posterior 

 two-fifths of the whorls between the sutures. Anterior three-fifths 

 marked by strong, broad, low, rounded, slightly protractive axial 

 ribs, which are strongest at their junction with the sulcus, beyond 

 which they scarcely extend. The type has lost the early whorls; 

 upon the first of those remaining there are 10 and upon the rest, 12 

 ribs. Intercostal spaces about one-half as wide as the ribs. On 

 account of the closely appressed summits, the sutures are poorly 

 defined. Base of the last whorl moderately long, marked by the con- 

 tinuations of the ribs, which gradually weaken in strength as they pass 

 forward. Entire surface of the spire and base marked by lines of 

 growth and numerous, closely crowded, fine, wavy, spiral striations. 

 Posterior angle of aperture acute, sinus below the keel at the summit; 

 columella sigmoid, covered by a thin callus which also extends over 



