216 MR. CRAVEN ON SHELLS FROM USAMBARA. [Mar. 16, 



Dimensions : — Length 5*6 millims., diameter of last whorl 2, 

 height of aperture r2, breadth of aperture 1. 

 Locality. Nossi-Be Island, in coifee-plantations. 



Paludina colbeaui, sp. nov. (Plate XXII. fig. 5.) 



Shell turbinate, perforate, opaque, dark greenish black, coarsely 

 striated by the lines of growth ; apex obtuse, spire acuminate ; 

 whorls 6, very convex, the last occupying about two thirds of the 

 entire shell, the upper ones tabulated ; interior of shell of a pale 

 neutral tint ; labrum thin, simple, of a brown colour ; columella 

 arcuate and somewhat reflexed over the umbilicus ; basal margin of 

 the aperture slightly effuse and angular ; umbilicus small but well 

 defined ; suture simple. 



Operculum corneous, black, pyriform and concentrical ; nucleus 

 subcentral. 



Dimensions : — Length 1 1 millims., diameter of last whorl 6, 

 height of aperture 5*5, breadth of aperture 4. 



Locality. Nossi-Be Island, in a sluggish stream running through 

 coffee-plantations. 



I name this species after my friend M. Jules Colbeau, of the 

 Societe Malacologique de Belgique. 



3. On a Collection of Land and Freshwater Shells made 

 during a short Expedition to the Usambara Country in 

 Eastern Africa, with Descriptions of seven new Species. 

 By Alfred E. Craven, F.R.G.S., F.L.S., F.G.S., F.Z.S., 

 &c. 



[Eeceived March 1, 1880.] 

 (Plate XXII.) 



Helix mozambicensis, Pfr. P. Z. S. 185.5, p. 91, pi. 31. fig. 9. 

 Very plentiful at Pangani, Marongo, and Magila. 



Helix usambarica, sp. nov. (Plate XXII. fig. 6.) 

 Shell depressedly turbinate, umbilicate ; apex obtuse, spire de- 

 pressed ; whorls 6, gradually increasing ; the upper ones rather con- 

 vex and the last very convexedly rounded and not descending ; the 

 two apical whorls smooth, the next three obliquely and the last 

 flexuously lirate ; epidermis very glossy, of a rich brown above, and 

 of a paler brown beneath ; shell beneath epidermis nearly white ; 

 interior of shell of a pale purplish white ; aperture semiluiiar, as 

 broad as high ; labrum thickened and slightly reflexed ; columella 

 somewhat straightened obliquely ; suture deep and well marked ; 

 umbilicus very deep and large. 



The young shells are very thin, glossy and transparent. 



