PSEUDOGLESSULA. 159 



ture. Peristome simple, unexpanded, the margins joined by 

 a thin parietal callous. Length 28, diam. 11 mm.; aperture 

 11 mm. long, 6 wide (Pfr.) . 



Of the reproduction of this species d'Ailly writes as fol- 

 lows: "In several individuals we have found embryos to the 

 number of 8 to 18, in which the spire has about 3 whorls, and 

 the dimensions vary from 3.5 to 5 mm. long, 2.5 to 3 mm. in 

 diameter. They are whitish, with a tinge of green the color 

 of the adult shell beneath the cuticle. In the largest, the 

 peristome has a deep brown border, and in all of them the 

 last whorl is strongly angular, with the base nearly smooth, 

 engraved only Avith striae of extraordinary fineness. The 

 shape of the columella is exactly as in adults. The species 

 is ovo-viviparous. " 



2. P. DUSENI d'Ailly. PI. 61, figs. 1, 2, 3. 



Shell oblong- turrited, thin, strongly thread-ribbed ; whitish- 

 green under a rufous-brown cuticle, paler towards the apex, 

 here and there obsoletely streaked with darker, and readily 

 worn off on the apertural side. Spire turrited, the apex 

 cylindric, rather obtuse. Whorls 10%, convex, slowly in- 

 creasing, separated by deep sutures, embryonic whorls sub- 

 perpendicularly and regularly costulate with the exception 

 of the smooth mammillate vertex itself ; the riblets are gener- 

 ally evanescent below on the third whorl. Remaining whorls 

 somewhat irregularly sculptured with strong, oblique, slightly 

 arcuate ribs ; the last whorl somewhat over one-fifth the total 

 length with a thread-like carina below, rather flattened below 

 it, the costulas there transformed into strise. Columella 

 curved, involute, bordered with a white callous, obliquely 

 truncate, reaching to the base. Aperture subvertical, subte- 

 tragonal, bluish- white inside; peristome simple, acute, the 

 margins joined by a whitish very thin callous; right margin 

 regularly arcuate, basal margin nearly straight, almost hori- 

 zontal. Length scarcely 10, diam. 2.5, length of aperture 2, 

 width 1.33 mm. (d'Ailly). 



West Africa: Cameroons at Kitta and Ekundu Etitti 

 (Dusen). 



