Freshwater' Shells from Central Africa. 159 



millata ; anfract, 11, convexi, incroraeati liueis obliquis tenuibus 

 striiiti ; apcrtura parva, acute ovalis, longit. totius ^ SBquana ; 

 columella arcuata, antice truucata. 

 Longit. 15 millim., diara. ;i| ; apertura 3 louga, 1| lata. 



Hah. Mamboia, at an altitude of 4000 to 5000 feet (Last). 



The two specimens of this species at liand are probably not 

 fnll-groNvn, as a faint angulation at the periphery of the body- 

 wliorl suggests this opinion. In that case the number of 

 ■whorls and the proportion of the aperture to the total length 

 may hereafter require modification. S. involuta, Gould, is 

 similarly coloured, but is a larger and thicker shell. 



Stenogyra {SuhuUna) Emini. (PI. V. fig. 19.) 



Testa elongata, gracilis, pyramidalis, subpellucida, pallide virescens 

 vel flavo-viridis, polita ; anfract. 1>, convexiiisculi, lente crescentes, 

 lineis incrementi obliquis levissime striati, sutura subprofunda, 

 obliqua, discreti ; apex obtuse rotundatus ; apertura parva, ovalis, 

 superne acuta, longit. totius I paido superaus ; columella bene 

 arcuata, antice oblique truucata, callo tenui albo induta. 



Longit. 16 millim. , diam. 3| ; apertura d\ longa, 2 lata. 



Hah. Mamboia, at an altitude of 4000 to 5000 feet {Last). 



This species bears a general resemblance to S. stricta, Poey, 

 from Cuba, but difi^ers in having much rounder whorls, a more 

 arcuate columella, with a distinct basal truncation. S. Lasti 

 is differently coloured and has shorter and more numerous 

 whorls. S. mammillata^ Craven, is a larger species with a 

 strongly puckered suture. 



Stenogyra [Suhulina) intermedia^ Taylor. 



Testa gracilis, superne parum angustata, subpellucida, stramineo- 

 alba, nitons ; anfract. 8-9, convexiusculi, elongati, oblique tenu- 

 issime striati, superne infra suturara obliquam minute corrugata ; 

 apex rotundatus, obtusus ; apertura parva, ovata, superne acu- 

 minata, longit. totius 4- subaequans ; columella valde curvata, 

 antice abrupte truucata. 



Longit. 10 miUim., diam. 2^ ; apertura 2 longa, 1 lata. 



Hah. Mamboia {Last) ; Zanzibar {Oibhons). 



This is a pale straw-coloured glassy shell with rather long 

 whorls, which are minutely (not very distinctly) puckered 

 above at the suture. This feature is not mentioned by Mr. 

 Taylor in the original description (Quart. Journ. Conch, 

 vol. i. p. 282), nor is it depicted in the figure (pi. i. fig. 5), in 

 which the aperture is drawn rather too narrow. 



12* 



