LAND SNAILS FROM THAILAND — SOLEM 625 



adults are, respectively, 25.0, 23.2 and 23.0 mm. high; h/d ratio 1.91, 

 1.86 and 1.77; with 6, 5%, and 5% whorls. 



3. Three shells from Nong Khor (USNM 363620), southeast 

 Thailand, have the spotting and streaking intensified and extending 

 onto the body whorl. However, the basal banding is absent in one, 

 the second is the same as in number 2, and the upper band is split into 

 two on the third. There is no trace of a columellar color patch. They 

 are 23.4-26.1 mm. high, h/d ratio 1.89-1.96, whorls 6 to 6%. 



4. A single adult from Krabin (USNM 363621), central Thailand, 

 has a reddish columellar suffusion, the columellar bands replaced 

 by a row of spots, a yellow subsutural band, and rather reddish 

 brown radial blotches that do not reach the suture (pi. 1, fig. 6). 

 It is 25.2 mm. high, h/d ratio 2.03 with 6% whorls. 



5. A worn adult from Sriracha (USNM 405892), southeast 

 Thailand, has the purplish-brown basal bands, and longer, more 

 widely spaced radial streaks. 



6. A juvenile shell from Nong Vang (USNM 384158a), southeast 

 Thailand, has the color pattern, including reddish patch, of the type 

 figures of A. areolatus. The only change from the type "5" is the 

 angle of the radial streaks. 



7. Specimens from Pak Jong, (USNM 365464, USNM 405908), 

 eastern Thailand, Hoi Yang (USNM 420291), near Sriracha, south- 

 eastern Thailand, and ThaLo (USNM 419193), Peninsular Thailand, 

 show minor variations of yet another color pattern. They have the 

 reddish columellar patch, two basal bands (becoming obsolete on 

 one Pak Jong juvenile), and reddish to purple radial markings of the 

 above forms, but differ in possessing a peripheral spiral yellow band 

 (pi. 1, fig. 7) that stands in sharp contrast to the whitish background 

 between the radial streaks. The radial streaks may be narrow, wide, 

 crowded, or widely spaced. 



A worn shell from Koh Samet (USNM 384154a), an island in the 

 Gulf of Siam, Southeast Thailand, could not be referred to any color 

 variety. 



Amphidromus semitessellatus (Morlet, 1884) 



Plate 2 (figs. 2-6) 



Bulimus {Amphidromus) semitessellatus Morlet, 1884, Journ. dc Conch., vol. 32, 



pp. 387-388, pi. 11, figs. 2, 2a [Laos]. 

 Amphidromus semitessellatus (Morlet). — Laidlaw andSolem, 1961, Fieldiana, Zool., 



vol. 41, no. 4, p. 564. 



Specimens from Sam Roi Yot (USNM 420457, USNM 420458) 

 and Nakon Sritamarat (USNM 419814) in Peninsular Thailand and 

 Srakeo (USNM 419811), southeast Thailand, are tentatively grouped 

 under this name. Size variation in the Sam Roi Yot specimens is 

 summarized in table 1. 



