319 



DESCRIPTION OF A NEW SPECIES OF PELTATUS FROM BRITISH 



EAST AFRICA. 



By J. 11. LE B. ToMLix, M.A. 



Bead 14th May, 1915. 



Peltatus poltsxephes,^ n.sj). 



Shell narrowly umbilicate, depressedly turbinate, thin, with suture 

 slightly marked ; whorls 5, rounded, increasing rapidly, the nltiraate 

 and penultimate being somewhat flattened above, while the first three 

 whorls rise in a rather acute spire ; apical whorl smooth and more or 

 less shining, tlie other four being marked with fairly regular lines of 

 growth — much finer and closer together on whorls two and three than 

 they are on the two last; colour olivaceous, with an endlessly variable 

 series of chalky-wliite bands ; the bands vary greatly in width and in 

 number, sometimes being reduced to mere threads of white, or they 

 coalesce broadly as in forms of Helix nemoralis ; rarely the shell is all 

 but white with faint indications of olive bands ; the outline of tlie 

 aperture, if completed, would almost form a circle, but is slightly 

 flattened in the plane of the spire ; margin of aperture acute, regularly 

 curved; columellar margin reflected over the umbilicus. Diam. 

 maj. 12, min. 10mm.; alt. 9rani. 



Hah.— Telia Hills, British East Africa, between 4,500 and 

 6,000 feet. (W. Feather.) 



By Mr. Gude's advice I place it in the genus Peltatus, on account 

 of its close resemblance to P. cotyledonis (Benson), = and lie has also 

 been kind enough to furnish me with the following particulars in 

 which P. poli/stephes differs from P. cotyledonis ; the whorls increase 

 more rapidly, the last whorl being proportionately much wider; they 

 are also more tumi<l and more strongly transversely striated by the 

 lines of growth, in fact it might almost be stated that P. polys'tephes 

 is finelv irregularly ribbed. The aperture is more transversely dilated 

 and the columellar margin is a little more oblique. 



^ Tro\v(TT€(pT)s = decked with many wreaths. 



2 Cf. Godwin-Austen in Ann. Mag. Nat. Hist., ser. vin, vol. ix, p. 134, 191^ 



