326 Annals of the South African Museum. 



anterior margins somewhat tumid. Ornamentation consists of 

 strong, slightly curved, transverse rihs — about nineteen on a whorl 

 — separated by broader furrows. The ribs are more or less com- 

 pletely interrupted by a spiral furrow at a short distance in front of 

 the suture, but appear again near the suture. The transverse ribs 

 and furrows are crossed by small spiral ribs placed at regular inter- 

 vals. Columella with three oblique folds. 



Remarks. — The generic position of this species is somewhat 

 uncertain since the character of the aperture is unknown. Gries- 

 bach referred it to Cerithium. The specimen which he figured does 

 not show the columella, but in another example in his collection two 

 of the whorls are broken across exposing the columella, on which 

 three folds, resembling those of Turris, are seen. It should be 

 noted that Griesbach's figure is enlarged about 1^. 



Family CANCELLAKIID.E. 



Genus CANCELLAEIA, Lamarck. 



Cancellaeia mebidioxalis, sp. nov. 



Plate XL., figs. 10, 11. 



Description. — Shell ovate. Spire short, forming about a quarter 

 of the entire length of the shell, and consisting of three or four 

 flattened whorls. Spiral angle 82°. Last whorl large, ventricose, 

 with a sulcus on its posterior part having a more or less sharp 

 border in front and a tumid ridge near the suture. 



Last whorl ornamented with from thirteen to fifteen strong, broad 

 transverse ribs which extend across the posterior sulcus, but are less 

 prominent on that part. About twelve strong, rather narrow spiral 

 ribs cross the transverse ribs and their interspaces. The transverse 

 ribs become rather more prominent at the margin of the sulcus, 

 producing a tuberculate appearance. In the sulcus spiral ribs 

 are either absent or very small. Numerous fine ridges are present, 

 running parallel with the transverse ribs. On the penultimate 

 whorl similar ornamentation occurs, but the whorls near the apex 

 appear to be nearly smooth. 



Aperture large, angular and canaliculate behind. Outer lip thick, 

 with folds corresponding to the spiral ribs; curving regularly except 

 at the level of the sulcus where it is slightly angular. Inner lip 

 with a thin callus extending on to the whorl. Columella with two 

 oblique folds in front of the middle. Anterior canal bent. 



Length 25 mm. ; breadth 17 mm. 



