1881.] SUMATRA AND BORNEO. 620 



becoming piukish grey at the apex, narrowly umbilicated, whorls 6, 

 oblique arcuate, sculptured with lines of growth and concentric 

 finely granular strife, producing a shagreened appearance, especially 

 on the last whorl, which is also considerably wrinkled, and bears a 

 somewhat raised ridge or keel at the periphery, which, however, 

 does not produce an angle, not descending in front. Whorls of the 

 spire only a little convex, the last large, rather ventricose. Spire 

 shortly conical, with the apex obtuse. Aperture large, broadly ob- 

 liquely lunate, of a somewhat mauve tint within. Peristome thin, 

 simple, only very shortly expanded over the umbilicus. 



Hab. Mount Sago, at an elevation of 2000 feet, only one specimen 

 found, in a decayed trunk. Like the rest of the Nanina I found 

 in Sumatra and Borneo, this also is sinistral. Greatest diameter 

 40 millim., height 31 millim. 



7. Helix (Nanina) maarseveeni, sp. nov. (Plate LV. fig. 2.) 



Shell perforate, sinistral, depressedly trochiform, thick, of a light 

 brown horn-colour, somewhat paler round the umbilicated region. 

 Spire conically depressed, with the apex obtuse. Whorls 7, sculp- 

 tured with feebly granulated, obliquely arcuate lines of growth, and 

 increasing slowly; last whorl with a very acute pale keel about the 

 middle, below the carina rather concave than convex, sculptured 

 like the upper surface, the lines being rather flexuous. Aperture 

 oblique, angularly lunate. Peristome thick ; upper margin above 

 the keel short, obhque, rectilinear, the basal very arcuate, towards 

 perforation somewhat expanded. Greatest diameter 33 millim., 

 axis 14 millim. 



Hab. Sidjoendjoeng. I have associated the name of Mr. Maar- 

 seveen (the Assistant Resident at Sidjoendjoeng) with this shell, of 

 which I only found three specimens. 



A near ally in form and colour is H. hugonis, Pfr., from La- 

 buan ; but H. maarseveeni has an extra whorl, is umbilicated, and 

 the spire is considerably less elevated ; and the granular sculpture 

 in H. hugonis is much stronger. H. maarseveeni comes much 

 nearer Helix mindaiensis^ found by me in Borneo ; but that has 

 only six whorls. 



8. Helix smithi, sp. nov. (Plate LV. fig. 3.) 



Shell thin, orbicular, umbilicated, flatly depressed, semitrans- 

 parent, of a greyish white colour, covered with a thin epidermis of 

 a light horn-colour, spire flattened. Whorls 4, flattish, sculptured 

 with fine lines of growth, the last slightly descending at the mouth, 

 broad, with a strongly marked obtuse keel, and a broad distinct 

 groove above, below convex, obtusely ridged round the deep umbi- 

 licus. Aperture large, subquadrangular, oblique. Peristome thin ; 

 outer margin expanded, reflexed, especially in the umbilical region. 

 Greatest diameter across 21 milhm., height 8 millim. 



Hab. Paio, Sumatra. Two specimens found (only 1 adult). 



Helix smithi is nearly allied to H. caseus, Pfr., from Siam ; 

 but the latter differs in having a less acute keel on the last whorl, 



