48 C^CILIOIDES, SECT. GEOSTILBIA. 



with a well -impressed suture, the last whorl one-third the total 

 length. Aperture piriform, the outer margin simple, unex- 

 panded; columellar margin dilated, reflexed, appressed, making 

 an angle with the basal margin. Length 4, diam. 1.25 mm. 

 (Crosse). 



Comoro Is.: Combani, Mayotte (Marie). 



Geostilbia comorensis MORELET, Journ. de Conch. 1883, xxxi, 

 p. 196, pi. 8, f. 7. 



Differs from G. mariei by its more slender shape, with longer 

 spire of two more whorls, and a shorter aperture. 



45. C. MARIEI (Crosse). PI. 4, figs. 65, 66. 



Shell imperforate, subcylindric, thin, polished, diaphanous, 

 hyaline, whitish. Spire rather long, the apex abruptly rounded, 

 very obtuse; suture impressed. Whorls scarcely 4, nearly flat, 

 slightly convex, the last very little descending, shorter than the 

 spire. Aperture regularly elongate-piriform, colored within 

 like the outside. Peristome simple, whitish, the margins joined 

 by a thin callus. Columellar margin somewhat thickened, 

 having an appearance of truncation, hardly reaching to the 

 base; basal margin rounded; outer arched forward, subacute. 

 Length 3, diam. 1 mm. (Crosse). 



Nossi-be Island: Calempo (E. Marie, type loc. ); Mayotte, 

 Comoros (Marie). 



. Geostilbia. mariei CROSSE, Journ. de Conch yl. 1880, p. 149; 

 1881, p. 200, pi. 8, f. 5; 1883, p. 195; in Grandidier's Hist. 

 Madag., Mollusques, pi. 19, f. 8. 



This form has a shorter spire and longer aperture than C. 

 gundlachi. 



46. C. STUHLMANNI (Martens). PI. 4, fig. 70. 



Imperforate, elongate, finely and regularly striate, translu- 

 cent, yellowish-vitreous; 5 whorls, the first globular, smooth, 

 the following rapidly increasing, rather flat, with deep, some- 

 what step-like suture, which is more oblique between the penult, 

 and last whorls. Aperture rather oblique; outer margin ap- 

 proaching rectilinear, thin, simple; lower margin broadly 

 rounded. Columellar margin thick, white, obliquely truncate 



