SOUTH AFRICAN MARINE MOLLUSKS. 109 



neighbor is also a little wider than the other spaces. The spiral 

 grooves are crossed by numerous, very slender, somewhat irregularly 

 spaced, axial threads. Sutures strongly constricted, usually showing 

 the peripheral cord. Periphery of the last whorl marked by a strong 

 cord which is separated from the supraperipheral cord by a groove as 

 wide as that which separates this from its posterior neighbor. Base 

 short, slightly rounded, marked by two low, broad, spiral cords which 

 divide the space between the insertion of the columella and the 

 peripheral cord equally, the spaces separating them being about equal 

 to the cords in width and crossed by numerous, very slender, raised, 

 axial threads. Aperture (fractured in all our specimens) strongly 

 channeled anteriorly; outer lip rendered sinuous by the external 

 sculpture; columella almost straight, strongly reflected over the 

 reinforcing base, a callus extending over the parietal wall. 



The type consists of the seven last whorls, which measure: Length, 

 9.5 mm.; diameter, 3 mm. It and another specimen, Cat. No. 1S6807 

 U.S.N.M., come from Port Alfred (Col. No. 173). The second speci- 

 men shows an intercalated spiral cord between the second and third 

 keel and another between the third and fourth, almost equaling the 

 keels in strength on the last volution. 



Three additional lots, all from Port Alfred, are in the collection of 

 the United States National Museum. Cat. No. 227722, two speci- 

 mens (Coll. No. 817). Cat. No. 249683, two specimens (Coll. No. 

 955). Cat. No. 249675, two specimens (Coll. No. 947). 



Family CERITHIOPSIDAE. 



Genus CERITHIOPSIS Forbes and Hanley. 



CERITHIOPSIS (CERITHIOPSIS) ALFREDENSIS, new species. 



Plate 5, fig. 9. 



Shell elongate-conic, light chestnut brown, with the early whorls 

 wax-yellow. (Nuclear whorls decollated, the last one only remain- 

 ing, which is smooth.) Postnuclear whorls almost flattened, marked 

 with three strong spiral cords of which the first is at the summit, while 

 the third is about as far above the suture as it is separated from the 

 median. The latter is about halfway between the first and third. 

 The spaces between the spiral cords are about as wide as the cords. 

 In addition to the spiral sculpture, the whorls are marked by axial 

 ribs which are almost as strong as the spiral cords. Of these ribs, 18 

 occur upon the first to fifth, 20 upon the sixth, 22 upon the seventh, 

 24 upon the eighth and the penultimate turn. The junction of the 

 axial ribs and the spiral cords form prominent tubercles which are 

 truncated posteriorly and slope gently anteriorly. The spaces 

 inclosed between the axial ribs and spiral cords are well rounded, 



