bartsch: land shells of Palawan passage 367 



The last turn is usually light near the summit, then girdled with a 

 broad, dark area which is of the same color as the dark area of the 

 base but is separated from this by a narrow light zone at the pe- 

 riphery. The dark coloration of the last turn may be green or light 

 coral-red or the latter overlaid with green. The base may be uni- 

 color, i. e., white, yellow, green, red, or brown, or it may have one 

 or two bands of yellow, brown, or red. The portion of the last 

 whorl adjoining the columellar callus is usually coral-red. The 

 interior is white, bluish, or pinkish, the peristome white or edged 

 with purplish brown. 



The table on page 363 gives additional data as to number of 

 whorls and shell measurements. 



The specimens which I have seen from Balabac Island show a 

 lesser variability in coloration than those from Bancalan, to which 

 they bear the greatest resemblance. There is here a much greater 

 tendency to spiral banding of the base than in the shells from any 

 of the other islands. All of the specimens of Amphidromus versi- 

 color weberi examined have a white peristome but in Amphidro- 

 mus versicolor higginsi this is frequently dark. In measurements 

 they agree best with the shells from Bancalan Island, i.e., Amphi- 

 dromus versicolor higginsi. 



The present sending by no means completes the survey of the 

 Palawan Passage region, for as yet we know nothing of the Amphi- 

 dromus inhabitants of the three large islands Bugsuk, Pandanan, 

 and Ramos, nor do we know anything about the group on the 

 lesser islands of Apo, Bowne, Canimeran, Patongong, Gabung, 

 Byan, Canabungan, Secam, Malinsono, Sanz, and Paz. Then, 

 too, the many islands off the north coast of Borneo should con- 

 tribute a large amount of information that should tell us some- 

 thing of the derivation of the forms in our domain which are 

 undoubtedly of Bornean stock. 



