240 ZOXITID-^. 



sculptured above, smooth and polished on base ; narrowly or not 

 perforated. Although possessing shell-lobes, the position of the 

 right shell-lobe is below the inner upper angle of the peristome, 

 and plays only over the lower surface of the shell — a position 

 different from that in Macroclilamys. The animal has a very 

 hooked lobe above the mucous pore. 



The differences between this genus and JlncrocJilamys are shoAA^n 

 in the description of the animal of H. anccjis below.] 



364. Holkeion anceps, Gould (CaracoUa), Bost. Jour. N. H. i\, 1844, 

 p. 454, pi. 24, fig. 4; Pfr. (Helix) Mon. Hel. \, 1847, p. 80; 

 H. 4- T. (Helix) C. 1. 1876, pi. 30, fig. 1 ; Stol. (Rotula) J. A. S. B. 

 1871, 2, p. 233, pi. 17, figs. 1-3 (anatomy); v. Mart. Nanina 

 (Rotularia), JoMr. iiwji. Soc. xxi, 1889, p. 161; Gochoin-Austen, 

 Proe. Mai. Soc. ii, 1897, p. 174. 

 [F^■^efig. 79, A-D, p. 237.] 



Shell scarcely perforate, lenticular, sharply keeled, pale horny, 

 dull and obliquely plicately striated above, polished and with fine 

 radiating striation beneath, no longitudinal sculpture ; spire low, 

 conoidal, suture not impressed, bordered by a more or less distinct 

 line inside ; whorls 6, almost flat above, increasing slowly, the last 



Fig. 80. — Holkeion anceps. 



very little broader than the penultimate, convex beneath, com- 

 pressed beneath the keel ; aperture slightly oblique, angulately 

 lunate ; peristome thin, basal margin faintly arcuate, columellar 

 oblique, briefly reflected above. 



Major diam. 16, min. 14|, height 7| mm. 



Hah. Tenasserim; Mergui, Tavoy, and Moulmein ; also Sullivan 

 Island, Mergui Archipelago, and Northern Siam. 



[Found generally on trees and bushes (SfoUczka).'] 



Animal dark grey with a distinct greenish tinge. Sole divided 

 loncfitudinally into three tracts, that in the middle broader than 

 the others. Tail-gland with slightly thickened edges and a small 

 hook-like appendage above. The left shell-lobe (fig. 79, A) has below 

 the angular periphery a Ungulate process, reflected over the basal 

 part of the peristome, and ends A^ith another shorter process near 

 the shell-retractor; the right shell-lobe has a lingulate process 

 next to the pulmonary opening, and another broader one covering 

 the columellar lip. Dorsal lobe well developed. Genitalia (B, B') 

 rather peculiar ; the dart-sac or amatorial organ is very thick 

 and provided with a strong pointed papilla. Spermatheca very 

 lono- and slender. Vas deferens leading to a kale-sac, which gives 

 off an elongate flagellar appendage close to the junction and leads 

 to the bend of the penis, to which the retractor muscle is attached. 



