COILOSTELE. 341 



Var. isseli Bourguignat. Differs from C. paladilhiana by 

 the more lengthened shell, whorls more detached, more swollen 

 around the upper part and more separated by the deeper 

 suture; striae finer and closer; aperture more oblique and 

 shorter. In isseli the long lanceolate spire tapers gradu- 

 ally without being ventricose; in paladilhiana the spire is a 

 little swollen in the middle. Length 3.5, diam. 0.75 mm.; 

 whorls 7. Found in the torrent Kursi, near Aden. Prob- 

 ably an individual variation of C. paladilhiana. 



3. C. BOURGUIGNATI Jousseaume. PI. 50, fig. 5. 



Shell imperforate, very minute, elongate, mamillate at the 

 summit, cylindric in the middle, relatively tumid there, fra- 

 gile, diaphanous, becoming rather opaque after death, hyaline 

 or whitish, sharply striatulate, the striae close, regular, slightly 

 oblique. Spire long-cylindric, swollen-mamillate and very 

 obtuse at the summit. Whorls 7 to 8, the embryonic swollen, 

 median a little convex, slowly increasing, separated by an im- 

 pressed suture, the last whorl convex, relatively quite swollen. 

 Aperture very oblique, ovate, peristome acute, unexpanded, 

 very slightly thickened within; columella twisted, as though 

 plicate. Length 3, diam. 0.33, alt. aperture 0.33, width 0.5 

 mm. (Jouss.). 



Aden : drift debris of torrent on the plain of Mahala. 



Coelestele ~bourguignati Jouss., Bull. Soc. Malac. de France 

 vii, 1890, p. 95, pi. 3, f. 16-18. 



This handsome species, remarkable for the extreme obli- 

 quity of the aperture, has a mamillate summit, relatively so 

 large that the median whorls appear slim, and quite dispro- 

 portionate to the size of the summit and the last whorl 

 (Jouss.) . 



4. C. STENOSTOMA Jousseaume. PI. 50, fig. 8. 



Shell imperforate, elongate, exactly cylindric, not more 

 ample at base than at the summit, fragile, subopaque, whitish, 

 delicately striate, the striae close regular and suboblique. 

 Spire long-cylindric, scarcely tapering, obtuse at the summit. 

 \\ r horls 7, slightly convex or subplanulate, slowly increasing, 



