164 AMPHIDROMUS, GROUP VI. 



Bulimus citrinus, in part, REEVE, Conch. Icon. pi. 31, f. 187b. 

 Bulimus leucoxantlim MART., Monatsberichte der Berliner Akademie, 

 1864, p. 526; Ostas. Conch, p. 348, pi. 20, f. 11, 12. PFR., 

 Monogr. vi, p. 18. Amphidromus leucoxanthus MORLET, Journ. de 

 Conchyl., 1889, p. 127. A. perversus var. leucoxantha FULTON, 

 1. c., p. 60 (1896). (?)Bulimus citrinus SWAINS., Zool. Illustr., i, pi. 

 46 (?) Bulimus citrinus (var. perversu} SWAINS., Zool. lllustr., i, 

 pi. 47, right and left figures. B. perversus var., PFR., Conchyl. 

 Cab., Bid., p. 379, pi. 39, f. 26, 27. Bulimus leucoxarthus Mart., 

 PFR.-CLESSIN, Nomencl. Hel. Viv., p. 212, no. 156. 



Variable in form, and with the apex either white or dark ; having 

 a broad white band below the suture, the lip white behind, and not 

 adnate. The locality was unknown until Morelet placed specimens 

 collected by Pavie in Siam on record. Figure 74 is von Martens' 

 type. 



Specimens from Malacca (Cuming) before me have a strong, con- 

 vex lobe on the columella. in some not visible from in front but seen 

 in an oblique view. They have the white and yellow coloration 

 which gave the name leucoxanthus to the variety, and there is a 

 single black varix on the penultimate whorl. They are either 

 sinistral or dexlral, and one is perforate (figs. 76, 77). Some speci- 

 mens of A. aureus natunensis have a similar columellar fold. 



Other specimens (pi. 54, fig. 75) bearing the locality Cochin 

 China, are dextral, dwarfed, alt. 36, diam. 22, or a little larger ; 

 white and pale yellow, with numerous and wide varices ; which, as 

 they indicate growth-arrest, show that the conditions of life were 

 locally not favorable, hence probably the small size. 



Still another form (pi. 54, figs. 78, 79) referable to leucoxanthus 

 is dextral, brilliant orange, with the usual white zone and a small 

 white basal patch ; apex white ; varices one or none, but there is a 

 dark line at the periphery of the whorls of the spire, appearing above 

 the sutures or sometimes nearly covered ; and there are occasionally 

 some reddish dashes below the suture. The subsutural region is 

 markedly concave, and in one specimen the white band there is but 

 faintly indicated. The shell is very solid and strong, and the lip 

 well developed, the whole aperture faintly pinkish-white. 



The following species is closely allied, but has the parietal wall 

 blackish. 



