340 COILOSTELE. 



Coilostele scalaris Bs., Ann. and Mag. Nat. Hist. 3d. ser. r 

 xiii, p. 136 (Feb. 1864). PFR., Monogr. Pneumopomorum 

 Viv., suppl. 3, p. 370. Coelostele scalaris BGT., Descr. CceL 

 p. 10. NEVILL, Handlist Moll. Ind. Mus. i, p. 162. 



"Perfectly smooth, except that there are a few distant broad 

 varix-like ribs on the penultimate whorl " (Nevill). 



2. C. PALADILHIANA Nevill. PL 50, fig. 4. 



Shell turrite, nearly cylindric, imperforate, pellucid, hya- 

 line, glossy, sharply and regularly flexuously costulate. Spire 

 long, slightly tapering to the very obtuse apex. Whorls 6^ 

 to 7, but slightly convex, flattened, gradually and regularly 

 increasing in width and height; suture impressed, subdupli- 

 cated, a flat belt below it. Last whorl larger than the penult., 

 being measured behind one-fifth the total length, ascending 

 towards the aperture. Outer lip in profile straight, very ob- 

 liquely receding below. Aperture a little oblique, narrowed 

 transversely, a little dilated below, oblong, subelliptical, some- 

 what resembling a human ear reversed; the outer margin a 

 little produced and narrowly arcuate at the upper insertion. 

 Peristome unexpanded, subcontinuous, thin, a trifle thick- 

 ened; columellar margin continued obliquely from the par- 

 ietal wall, a little flexuous, and noticeably projecting at the 

 junction with the parietal wall; right margin elongated and 

 moderately arcuate. Length 3, diam. 0.75 mm. (Palad.). 



Aden : drift debris of the Kursi. 



Francescia scalaris PALADILHE, Annali del Mus. Civ. di Stor. 

 Nat. di Genova, iii, Dec. 1872, p. 10, pi. 1, figs. 1-4. Not 

 C. scalaris Bens. Cf. ISSEL, Annali vol. 4, p. 522. Coelostele 

 paladilhiana NEVILL, Handlist Moll. Ind. Mus. i, p. 162 

 (1878), based upon Paladilhe's description. Cozlestele ara- 

 bica BGT., Descr. Coal., p. 15 (1880), based upon the same 

 description. Coelostele sp., BLANFORD, Journ. Asiatic Soc. of 

 Bengal, vol. 44, 1875, p. 44. 



"Only distinct from the preceding [C. scalaris] by the dis- 

 tinct, almost microscopic striation, and the whorls being a 

 trifle less 'Cylindrical" (Nevill). Issel reports this species 

 from the arid islet Sek Sayd, near Massaua, the shells agree- 

 ing exactly with those from Aden. 



