AMPHIDROMUS, GROUP VII. 183 



delicately striatulate, glossy. Whorls 6-^-7, a little convex, the 

 upper 3 punctate-granulate, the last somewhat inflated. Aperture 

 rather oblique, subauriform, the peristome broadly expanded, a little 

 reflexed, labiate, bright purple, outwardly margined with black prolti- 

 mella twisted, excavated above, broadly appressed, joined with the 

 outer margin of the lip by a broad purple callus. Alt. 37, diam. 2(% 

 length of aperture 19, width 14 mill. (Mlldff.) 



Boloven Plateau, in western Annam, on the left bank of the 

 Mekong (C. Roebelen). 



Amphidromus hcematostoma MLLDFF., Nachrbl. d. Malak. Ges., 

 xxx, p. 74 (June, 1898). 



Von Moellendorff records two color-forms, of which the green one 

 may be considered typical. 



11 A. viridis. Shell green, becoming pale above, with a narrow 

 dark line at the suture and a slightly wider yellow band disappearing 

 above ; the early whorls whitish, the last one with a rather wide 

 bright yellow zone around the columella. 



"B. varians. Shell bright yellow, the upper 3 whorls pale red- 

 dish, succeeding whorls with very wide, curved, chestnut streaks, 

 last whorl uniform yellow.' 



" There lie before me three entirely similar examples of the green, 

 two of the yellow form. Notwithstanding the conspicuously diverse 

 color and pattern, they belong together specifically, for the contour, 

 the characters ot the aperture and all the rest are quite identical. 

 By the fine blood-red lip, which especially in the green form con- 

 trasts beautifully with the ground-color, it certainly belongs to the 

 group of A. schomburgki, with which it also shares the finely punctate 

 embryonal whorls ; but still in form, color and marking they are very 

 different." (Mlldff.) 



A. LAOSIANUS Bavay. PI. 62, figs. 60, 61. 



Shell either sinistral or dextral, oblong-conic, imperforate. 

 Whorls 7J, a little convex (the last more so), joined by a distinct, 

 slightly margined suture, which is sometimes black-bordered on the 

 earlier whorls, sometimes not bordered, or with a white sutural band 

 on the last whorl ; longitudinally minutely striate ; the first ones of a 

 buff-white tint, two or three later whorls closely striped longitudinally 

 with brown, the stripes of unequal intensity, extending to the suture ; 

 last whorl with a brown varix-band. Aperture oval, long, angular 



