SOUTH AFRICAN MARINE MOLLUSKS. 75 



The type and another specimen, Cat. No. 249709, U.S.N.M., come 

 from Port Alfred (Coll. No. 981). The type has six postnuclear 

 whorls, and measures: Length, 4 mm.; diameter, 1.2 mm 



Genus TURBONILLA Risso. 

 TURBONILLA tPTYCHEULIMELLA) ERNA, new species. 

 Plate 16, fig. 2. 



Shell very small, elongate-conic, bluish white, translucent. Nuclear 

 whorls at least two, well rounded, forming a depressed helicoid spire, 

 the axis of which is almost at right angles to the axis of the succeeding 

 turns. The nuclear spire is about one-fourth immersed in the first 

 of the succeeding whorls. Postnuclear whorls slightly rounded, 

 strongly appressed at the summit, marked by extremely feeble, 

 almost vertical axial ribs which are so poorly defined that they can 

 scarcely be counted. In addition to the axial sculpture, the entire 

 surface of the whorls is marked by closely spaced, microscopic, spiral 

 striations. Sutures well constricted. Periphery of the last whorl 

 somewhat angulated. Base short, well rounded. Aperture elongate- 

 ovate; posterior angle obtuse, outer lip thin, imier lip strongly 

 curved and slightly reflected; parietal wall covered by a thin callus. 



The type and another specimen, Cat. No. 250371, U.S.N.M., come 

 from Port Alfred (Coll. No. 1244). The type has seven postnuclear 

 whorls, and measures: Length, 3 mm.; diameter, 0.7 mm. 



TURBONILLA (CHEMNITZIA) GEMMULA Smith. 



Cat. No. 186847, U.S.N.M., contains two specimens of this species 

 from Port Alfred (Coll. No. 214). 



TURBONILLA (CHEMNITZIA) KRAUSSI Clessin. 



Cat. No. 186843a, U.S.N.M., one specimen from Port Alfred (Coll. 

 No. 210a). 



TURBONILLA (PSELLIOGYRA) ADABA, new species. 

 Plate 15, fig. 5. 



Shell broadly elongate-conic, white. Nuclear whorls well rounded, 

 smooth, obliquely immersed in the first of the succeeding turns, above 

 which the tilted edge of the last volution only projects. Postnuclear 

 whorls almost flattened, very strongly, tabulatedly shouldered at the 

 summit, crossed by strong, very regular, somewhat sinuous, slightly 

 protractive, axial ribs, of which 20 occur upon the second and third, 

 22 upon the fourth and fifth, 24 upon the sixth, and 28 upon the 

 penultimate turn. These ribs extend prominently from the shoulder, 

 which they render crenulated, to the periphery of the turn. Inter- 

 costal spaces a little wider than the rib. A spiral cord in the 

 intercostal is present about one-fifth of the space between the sutures 



