321 



DESCRIPTION OF A NEW SPECIES OF DYAKIA. 



By G. K. GuDE, F.Z.S. 



Bead 14th May, 1915. 



DyAKIA VENATOR, n.Sp. 



Shell sinistral, narrowly umbilicated, conoid, finely and closely 

 striated, the striae cut into minute granules by close spirals, pale 

 fuscous, lustreless ; spire elevated, apex acute, suture linear. 

 Whorls 6^, flattened above, tumid below, excavated around the 

 umbilicus, increasing slowly and regularly, the last whorl keeled at 

 the periphery, sulcate below the keel, not descending in front, 

 slightly dilated towards the aperture. Aperture oblique, semi-lunate, 

 margins slightly convergent; peristome thin, reflexed, upper margin 

 nearly straight, descending, outer and basal margins strongly curved, 

 columellar margin ascending, slightly overhanging the narrow 

 umbilicus. Diam. maj. 25, min. 21*5mm. ; alt. 12 mm. 



Hab. — Borneo. Type in my collection. 



This new species is based on two specimens from the Nevill 

 Collection, purchased as fur back as 1904, and a third specimen from 

 the same source in Mr. Ponsoiiby's collection. 



It appi'oaches Di/akia bnsajiensts, Godwin-Austen, var. concolor, 

 Smith,' but the latter has the whorls more convex above and more 

 rapidly increasing, the strife and spirals are much finer and closer, 

 the lower side is shining and strongly polished, and the umbilicus is 

 narrower. Another allied species is Dijalcia sitbdebilis, Smith,- but 

 that shell is darker in colour, the whorls are still more flattened, are 

 margined below the suture, and provided with a peripheral band ; 

 the striaj and spirals are also finer. 



JIv second specimen possesses only 6 whorls and measures : diam. 

 maj. 22-2o, min. 20-25 mm. ; alt. 11-75 mm. Mr. Ponsonby's shell 

 has tlie same diameter as the type, but is a little more depressed, 

 measuring: alt. 23-5 mm. 



^ Proc. Zool. Soc, 1895, p. 103. '^ Loc. cit., p. 104, pi. ii, fig. 11. 



