Nanina, Helix, Amphidiomus, and Porphyrdbaphe. 101 



strias, acutely keeled, last half- whorl with fine spiral decussated 

 striae above; whorls 5, slightly convex, last compressed at 

 outer margin ; aperture very oblique ; peristome somewhat 

 thickened and slightly pressed outwards at basal margin, but 

 not reflected ; ground-colour fulvous brown, interior of aper- 

 ture whitish ; extremities of peristome connected by a thin 

 callus. 



Height 13 millim., maj. diam. 32 raillira. 



Type in British Museum. 



Loc. Khasi Hills, N.E. India. 



This form comes between oxytes and cychplax of Benson. 

 In form it is like the former, but is smaller, of a darker colour, 

 and easily separated by its granular sculpture. It is flatter 

 and much more sharply keeled than cydoplax, and has the 

 granular striee all over the shell, whereas cydoplax is almost 

 smooth on the underside. 



Helix {Xenothauma) Baroni, sp. n. ' 



Shell depressly orbicular; umbilicus deep, about 6 millim. 

 wide, funnel-shaped, keeled at the margin and finely concen- 

 trically lirate within ; colour dirty white, with 5 or 6 raised 

 and somewhat granular spiral lirae on each whorl, between 

 which are fine spiral strise ; the underside has the same sculp- ' 

 ture as above, but the lines of growth are rather more strongly 

 developed than on the upper part; whorls 4^, almost flat, the 

 last whorl compressed at outer margin and very acutely 

 keeled, sharply deflected anteriorly, descending to just below 

 the edge of the umbilicus ; nucleus prominent, consisting 

 of 2^ whorls, distinctly separated from the rest and sculptured 

 with close-set, microscopic, oblique striae, decussated with 

 fine spiral lines ; peristome continuous, quite free, of an' 

 irregular triangular Ibrm, the compressed keel forming a; 

 narrow channel within, thin, broadly expanded, partly con- 

 cealing the umbilicus; margins white; interior of aperture of 

 a light brownish colour. 



Height 12 millim., maj. diam. 30 millim. 



Type in British Museum. 



Loc. Rio Yonan, Peru, 4000 feet {G. T. Baron). 



This remarkable form, were it not for its entirely different 

 nucleus, would fit well into the Madeiran group of Geomitra, 

 its general resemblance to G. delphinula, Lowe, being very 

 close. There does not appear to be any known species fron^ 

 South America which bears any resemblance to this species,^ 

 whicii has more the appearance of certain European and North- ^ 

 African species, such as H. Gualieriana, Linn., //. violy, 



