African yon-marinr MuUugca. 513 



Streptostele (Ra/J'raya) constricta, sp. n. 

 (PI. XIV. fig. 40.) 



Shell very snuill, subaciculatc, rimatc, tliiii, soiiicwliat 

 silky, traMsj)arcnt, i)alc olivaceous. Spire produced, sides 

 slightly e(juve.\ al the 4lh whorl, apex rounded. ^VhorlsG^, 

 rather Hat, gradually, rather irregularly iuereasiug, the first 

 H sinootii, reiuaiudcr sculptured with taint, nearly straight, 

 \ertical rib-striae, which arc most visible in the impressed, 

 erenulatc suture. Aperture siibpiriform, broadly rounded 

 at base; peristome white, shining, thickened, and very 

 narrowly rellexed ; outer lip a little curved outward, very 

 slightly angulate forward and then receding slightly further 

 to the base ; columella concave, margin triangularly 

 thickened and expanded, forming a well-marked rima ; 

 callus pronounced ; dentition none. 



Long, l-l, hit. 1-2 ; apert., alt. M, lat. 0'75 ; last whorl 

 1*8 mm. 



Hab. Kknya, Kekumega (Percival). 



Very similar to S. cylindrica, but with considerably 

 stronger sculpture. 



Streptostele [Ralf'raya) unidentata, sp. n. 

 (PI. XIV. fig. 42.) 



Shell extremely small, rather elongate, subrimate, rather 

 tliin, silky, semitransparent, pale olivaceous. Spire pro- 

 duced, sides almost parallel, apex narrowly rounded. 

 Whorls G, rather convex, hardly iucreasing after the first ; 

 the first 2i smooth, remainder sculptured with compara- 

 tively strong, regular, straight, vertical strire ; suture simple, 

 rather impressed. Aperture piriform ; |)eristome white, 

 shining, thickened, minutely rellexed ; outer lip hardly 

 curved outward, very slightly angulate forward and then 

 receding a little less slightly to the base ; columella erect, 

 thickened, margin narrowly rcHexed, forming a minute rima; 

 callus none ; dentition consisting of a small sharp denticle, 

 which is woi clearly brought out in the tigure, near the 

 middle of the paries and an inward swelling, almost 

 amounting to a tubercle, at the angulation of the outer lip. 



Long. 2-8, lat. OU ; apert., alt. 05, lat. O'S ; last whorl 

 1"2 mm. 



Hab. N. Rhodesia, north bank of 11. Zambesi, Victoria 

 Falls {So per). 



A wonderful little species, remarkable alike for its minute 

 size ;uid well-marked dentition. 



