342 COILOSTELE. 



separated by a deep narrow suture, the last whorl little con- 

 vex. Aperture subvertical or suboblique, narrow, long ; peris- 

 tome unexpanded, a little thickened and spreading at the 

 base, thicker and reflexed at the columellar margin ; the mar- 

 gins joined by a callus. Length 3, diam. 0.5, aperture 0.33 

 x 0.25 mm. (Jouss.). 



Aden : drift debris of a torrent in the plain of Mahala. 



C. stenostoma Jouss., Bull. Soc. Malac. de France, vii, p. 

 96, pi. 3, f. 19-21, 1890. 



Very characteristic by its long-cylindric shape, almost as 

 wide at the summit as at the base; by the slightly convex 

 whorls, almost flat, and separated by a deep sutural gutter, 

 and by the remarkable narrowness of the aperture (Jouss.). 



5. C. AFRICANA Bourguignat. 



Shell imperforate, cylindric, smooth, diaphanous, glassy. 

 Spire long-scalariform, slightly tapering, mamillate at the 

 summit, apex very stout, very obtuse. Whorls 7, flattened, 

 strongly swollen around the suture, regularly and slowly 

 increasing, the last slightly larger, convex. Aperture very 

 oblique, suboblong, angular above, rounded below. Peris- 

 tome unexpanded, lightly thickened and whitish; columellar 

 margin arcuate, a trifle thickened, not plicate. Length 3, 

 diam. 0.75 mm. (Bgt.). 



Egypt : drift of the Nile at Damietta. 



Ccelestele a., BGT., Descr. Ccel., p. 11, 1880. JOUSSEAUME, 

 Bull. Soc. Malac. France VII, p. 88 (near Massouah). 



Differs from C. scalaris by the mamillar summit, closer coil, 

 there being 7 instead of 6 whorls in the same length, by the 

 very oblique aperture, well rounded basally, the arcuate colu- 

 mellar margin, not thickened, and without a fold above. As 

 in all other Crelesteles known to me, the columellar axis is 

 wanting above the penult, whorl (Bgt.). 



6. C. ^EGYPTIACA Bourguignat. 



The distinctive sign of this species is in the perfectly cylin- 

 dric shape. In C. scalaris and africana the shell enlarges 

 gradually in diameter. In ccgyptiaca the whorls are smaller, 



