BURTOA. 305 



on the last whorl. Spire short, very obtuse. Whorls 6, con- 

 vex, slowly increasing; suture quite deep. Last whorl ventri- 

 cose, more than two-thirds the total alt. Aperture noticeably 

 oblique, excised, angular above, retracted at the base. Whit- 

 ish inside, passing into bluish at the margins and columella. 

 Peristome very thin and fragile, etc. Length 48, diam. 33, 

 aperture 33 by 18 mm. (BoT., Moll. Afr. Equat, p. 96, pi. 

 4, f. 2). 



Usugara, in the Makata valley; Mikese, in the Mouere, 

 south of Lake Victoria Nyanza. 



2. B. JOUBERTI (Bourguignat). PL 35, fig. 21. 



Shell rimate-perf orate (the perforation open and deep), 

 large, oblong, the last whorl notably directed to the right, 

 rather solid and opaque; strongly striate and elegantly de- 

 cussated with fine spiral lines, wanting on the lower part of the 

 last whorl ; uniform fleshy-chestnut colored, roseate under the 

 cuticle. Spire produced-oblong, somewhat swollen-acuminate, 

 but obtuse at the apex. Whorls 7, convex, regularly and 

 rapidly increasing, separated by an impressed suture, the 

 last convexly oblong, somewhat more than half the total 

 length, strongly bent to the right, slowly descending at the 

 insertion. Aperture nearly vertical, ovate, angular above, 

 pearly white inside, at the margins, columella and parietal 

 callous wine-roseate. Peristome obtuse, a little thickened 

 within, a little spreading, more so at the base, roseate through- 

 out. Columellar margin robust, roseate, strongly reflexed, 

 obsoletely and broadly concavely channelled above; outer 

 margin slightly curving forward. Length 95, diam. 60, aper- 

 ture 48 by 37 mm. 



Unyanyembe, near Tabora, German East Africa. 



Burtopsis jouberti BGT., Moll. Afr. Equat., p. 99, pi. 2, f. 

 1 (1889). 



Smaller and less swollen than B. giraudi, with a relatively 

 much smaller aperture. 



3. B. SEBASMIA Bourguignat. PI. 30, fig. 17. 



Shell of very large size, deeply perforate, the perforation 



