304 BURTOA. 



gular above, subeffuse at the base; peristome straight, acute; 

 columella nearly straight, dilated above the axial crevice, 

 acute at the base ; margins joined by a strong callous. Length 

 89, diam. 55, alt. of aperture 52, width 30 rnm. (Grandidier) . 



Ridges near the Victoria Nyanza, southeast, in the direc- 

 tion of Kilima-njaro. 



Limicolaria bourguignati GRANDIDIER, Moll. Cent. Afr., 

 Bull. Soc. Malac. France, ii, 1885, p. 157, pi. 7, f. 1. Not 

 L. bourguignati Paladilhe, 1872, a species of Opeas. Burtoa 

 bourguignati BGT., Moll. Afr. Equat., p. 91 (1889). 



Var. BRIDOUXIANA Bourguignat. PI. 35, fig. 23. 



Shell with the perforation almost completely closed, ovoid- 

 elongate, thin, subtransparent, grooved except on the upper 

 whorls, the longitudinal stria? cut on the upper part of the 

 last whorl by spiral lines. Coloration of long, narrow, longi- 

 tudinal flames of chestnut-yellow, alternating with others of 

 a blackish shade. Spire regular, obtusely acuminate, of 8 

 slightly convex whorls, slowly increasing to the last. Suture 

 not deep. Last whorl convex, oblong, not over two-thirds 

 the alt. Aperture vertical, excised, lengthened oblong, 

 strongly angular above, the outer margin regularly arcuate, 

 a little retracted below. Peristome unexpanded, acute, the 

 columellar margin straight, reflexed in a long triangular dila- 

 tation, the lower angle of which reaches to the base of the 

 axis. Length 79, diam. 44, aperture 44 by 25 mm. 



Usugara, at Mont Kidete, between Kondoa and Mpuapua. 



Burtoa bridouxiana BGT., Moll. Afr. Equat, p. 92, pi. 4, 

 f. 3 (1889). 



This is apparently a young shell. The following from the 

 same region is much younger and may be allied: 



Burtoa lavigeriana Bourguignat. (PI. 30, fig. 19). 



Shell narrowly, very deeply perforate, small, relatively very 

 much swollen, very fragile, transparent, very finely striat- 

 ulate except on the embryonic whorls, decussate with fine 

 spiral lines on the upper part of the last two whorls. Cuticle 

 very fugacious, of a pale yellow with dark chestnut streaks 



