120 MR. G. NEVILL ON THE [Feb. 17, 



Helix (Xerophila) cespitum, Drap. 



This species, also near Menton, appears to differ widely, and, at 

 the same time, constantly, according to the altitude at which it 

 lives ; it is interesting to notice, in the " Couche marneuse " at Cape 

 Mortela, how an allied species, with narrow umbilicus, either HelLv 

 ferneri or a closely connected form, abounded at a certain depth, 

 associated with H. paretiana, how this species suddenly ceases at 

 a certain distance from the surface, its place being taken by the 

 widely umbilicate H. cespitum. 



Var. DiSMASTHiA, nov. 



Spire very little raised, often nearly quite flat, rather solid ; 

 whorls seven, scarcely convex ; last whorl compressed, scarcely de- 

 scending, not tumid at base ; umbilicus less open than in most forms 

 of H. cespitum ; aperture rather compressed, slightly produced, 

 columellar margin very oblique ; vividly coloured ; above coarsely 

 but regularly and closely striate, strite subobsolete at base. 



This form is abundant near the sea only, apparently not found 

 at any considerable altitude, where its place is markedly taken by 

 the next variety ; I found it also at Alassio, near Genoa. A. curiously 

 coloured form, common at both places, was of a nearly uniform 

 dark brown above, with a bright yellow belt at the periphery. 



Alt. \2\, diam. 211 millim. ; apert. alt. 9\, lat. lOf millim. 



Var. ALTicoLA, nov. 



Like the preceding a well-marked, characteristic, and constant 

 variety ; the two forms apparently do not, at Menton at least, run 

 into one another; the two almost seem to me specifically separable ; 

 some conchologists will doubtless consider them so ; the ana- 

 tomist will have to settle the question. At an altitude of 2000 feet 

 for certain (perhaps sooner), var. alticola takes the place of var. 

 dismasthia and is found in great abundance up to the very summits 

 of the mountains, over 4000 feet. 



Spire moderately raised, almost smooth ; the upper whorls sub- 

 obsoletely striate, openly and solariformly umbilicate, texture a good 

 deal thinner than in the preceding var. ; whorls seven, convex, last 

 whorl globosely rounded, tumid at base ; aperture nearly perfectly 

 round, the interior as high as broad, outer margin descending more 

 abruptly, the columellar one markedly less oblique, the peristome 

 less thickened within; coloration, above especially, less vivid. 



Alt. 18, diam. 27g; apert. alt. 13^, lat. (cum marg.) 14 millim. 



For comparison with the two preceding measurements, I give 

 below those of /i. cespitum aud its var. major as recorded by Pfeiffer 

 (Mon. i. p. 161). 



Diam. maj. 20, alt. 11 millim. 



Var. major— d^\&m. maj. 25, alt. 14 millim. 



Types of the two preceding varieties in Indian Museum, Calcutta. 



Helix (Xerophila) subcespitum, n. sp. 



I found a few subfossil specimens of this undoubtedly distinct 



