148 OPEAS, EAST AFRICA. 



British East Africa: Mamboya, at an elevation of 4-5000 

 ft. (Last). 



Stenogyra (Opeas) stenostoma SMITH, Ann. and Mag. 

 N. H. (6), vi, p. 160, pi. 5, f. 20. August, 1890. 



' ' This species has a long body- whorl and aperture, recalling 

 to mind the little Cecilianella acicula." 



20. 0. LIMPIDUM Martens. PL 15, fig. 72. 



Imperforate, conic-turrited, weakly and closely striate, 

 translucent, glossy, of glassy clearness. Whorls 9 to 9^, the 

 first globular, smooth, the second and third of nearly equal 

 size, strongly convex, the following regularly and slowly 

 increasing, convex, with rather impressed whitish sutures, 

 the last whorl rounded below. Aperture rather oblique, 

 rounded-squarish, comprising a little more than one-fourth 

 the length of the shell ; outer lip thin, scarcely arcuate ; lower 

 margin rather narrowly rounded, columellar margin vertical, 

 rather thick, white, narrowed below, and forming a distinct 

 angle with the basal margin. Length 11, diam. 3, aperture 

 2.66 x 1.75 mm. (Marts.} . 



East Africa: Bukende on the Issango (Dr. Stuhlmann). 



Opeas limpidum MARTS., Beschalte Weichthiere p. 127, pi. 

 5, f. 31. 



"Reminds one of Streptostele by the shape and luster of 

 the shell, but the columellar margin is not so distinctly twisted 

 and the outer lip is not thickened." The imperf orate axis 

 is unusual in Opeas, if the species really belongs here. 



21. 0. STREPTOSTELOIDES Martens. PI. 15, fig. 73. 



Elongated-conic' with an umbilical fissure, closely rib- 

 striate, with a yellowish-brown cuticle, in part deciduous; 

 very obtuse above. Whorls G 1 /^, scarcely convex, with a 

 rather deep suture, regularly increasing, the last rounded, 

 convex below. Aperture occupying one-fourth the total 

 length, of a rounded obliquely quadragular shape; peris- 

 tome unexpanded, the outer margin nearly vertical, receding 

 above; basal margin rounded; columellar margin vertical, 

 thickened above, and obliquely entering the interior of the 



