194 AMPHIDKOMUS, GROUP XI. 



A. SEMITESSELLATUS (L. Morlet). PI. GO, figs. 41, 42, 43, 44. 



Shell sinistral, slightly rimat^, rather solid, smoothish, striatulate. 

 Pale bu'ff, fading to white on the spire, the first 1^ whorls uniform 

 white minutely marked with brown at the apex, following whorls of 

 the spire with tioo spiral series of brown spots, those of the upper series 

 square or rhombic, the lower elongated ; the suture with a conspicuous 

 black or purplish border below ; last whorl uniform buff without mark- 

 ings other than the sutural band, or with a wide purple-black band 

 below the periphery and another encircling the columella. Aperture 

 white, half-oval, the peristome reflexed, white ; columella rounded, 

 dilated above and partially appressed ; parietal callus a transparent 

 film. 



Length 35, diam. 16, aperture with peristome 16^ mill, (type, figs. 

 41, 42). 



Length 29^-, diam. 15^, longest axis of aperture 15 mill. (figs. 43, 

 44). 



Cambodia: Mountains along the Mekong river below Stung- Trang ; 

 forests and mountains of Kampot at Kompong-Son ; Mountains of the 

 .Elephant chain. Siam: Sralceo (Pavie). 



J3ulimus (Amphidromus} semitessellatus L. MORLET, Journ. de 

 Conchyl., 1884, xxxii, p. 387, pi. 11, f. 2, 2er A. semitessellatus 



MORLET, J. de C., 1889, p. 128 FISCHER, Soc. d'Hist. Nat. 



d'Autun, iv, 1891, p. 117 FULTON, Ann. Mag. N. H. (6), xvii, 



p. 87. 



Rather more solid than most members of its group, and with a 

 special pattern of its own. The basal zones of the last whorl (figs. 

 43, 44) do not continue to the lip, or may be entirely absent, as in 

 Model's type (figs. 41, 42). 



A. XIENGENSIS L. Morlet. PI. 63, figs. 75, 76. 



Shell sinistral, narrowly perforate, elongate, conoid, subfusiform, 

 glossy. Growth-striae very fine on the upper whorls, gradually 

 becoming more prominent on the last whorl, near the aperture. Spire 

 conic, the apex bluish ; whorls 6-^-7, the two earlier yellow, those 

 following ornamented on a light yellow ground with long radial broivn 

 and curved flames, cut in the middle by a narrow yellow spiral zone; 

 , the suture bordered by a narrow yellowish zone below ivhich there is a 

 series of little brown spots. Last whorl having a continuous reddisli- 

 b run' n sufural zone, and on its upper part, a crowded series of brown 



