150 AMPHIDROMUS, GROUP IV. 



28, aperture 25 mill, (sinistral). Other specimens are duller yellow, 

 partly even yellowish-white, although collected alive. 



Still other Javan specimens agree with the typical form from S. 

 Celebes in the yellow color, blackish varices and lip-edge ; while still 

 others (pi. 51, fig. 51) are white, with several blackish varices, and 

 black-brown lip-edge, thug agreeing with the Celebes form niveus. 

 The specimen figured is from coll. G. H. Clapp. 



BORNEO. Mr. A. Everett collected two dextral specimens (pi. 

 51, fig. 52) at Sadong, West Sarawak, one of which Mr. E. A. 

 Smith has figured ; neither of them have black varices, and the 

 parietal wall is dark, as in atricallosus. Schepman reports similar 

 specimens from Mt. Sekedau and Mt. Dadap, coll. by Moret, but he 

 mentions that they have brown spots on the white zone near the 

 suture. * This form is probably a modification parallel to, rather 

 than genetically connected with A. atricallosus of the mainland, and 

 may be called form similis. 



Swainson has figured shells with the adnate lip, black bordered on 

 the reverse, of A., perversus, but of rather more elongate form, and 

 having a white zone below the suture. The locality is unknown, 

 and I do not know whether to think it a form of A. perversus or of 

 A. leucoxanthus. The white parietal callus and different lip would 

 se.em to remove it from A. atricallosus, though that species sometimes 

 buries the dark parietal color under a copious white layer. See 

 Bligh Catalogue, upper figure of first plate, and Zoological Illustra- 

 tions vol. i, pi. 46, under the name Bulimus citrinus. 



A. INTERRUPTUS (Muller). PI. 52, figs. 53, 54, 55, 56. 



Dextral or sinistral, imperforate, rather narrow, with high spire 

 and white apex; whorls 6^; ground-color yellow, either sulphur, 

 maize or paler tint, with a broad purplish zone on the base; marked 

 with numerous reddish-chestnut streaks, which are interrupted at 

 the periphery, and fall far short of the suture above, and on the base 

 become purplish-brown ; a white or yellow patch around the columella ; 

 these markings obsolete on the spire or appearing as short streaks 

 above the suture on the next to the last whorl. There is a dark 

 varix on the penultimate and sometimes another on the last whorl. 

 Aperture rather small ; lip white, reflexed and adnate, the edge of 

 the reflection generally brown. 



Alt. 47, diam. 25, aperture 23 mill. 



