158 AMPH1DROMUS, GROUP V. 



Alt. 38, diam. 21-J, longest axis of aperture, 19 mill. 



Engano Island, west from the south end of Sumatra (Dr. G. 

 Modigliani. Mr. Wm. Doherty). 



A. enganoen&is FULTON, Ann. Mag. N. H. (6), xvii, p. 71, pi. 6, f. 

 11 (Jan., 1896). HENDERSON, Nautilus xii, p. 15 (June, 1898). 



A very distinct species, varying notably both in coloration and 

 size. Fulton describes it as with the " ground-color either yellow or 

 rich brown, sometimes in the latter case with two or three darker 

 brown spiral bands;" arid he figures a brown specimen (fig. 53). 

 The shells collected by Doherty (figs. 54, 55, from coll. John B. 

 Henderson, Jr.) are olivaceous brown, fading above as in A. aureus, 

 though sometimes sulphur-stained on the spire, and either with or 

 without four* brown zones. The convex columella, impressed at its 

 root, and with more or less produced or lobed outer edge, is charac- 

 teristic of all colors and sizes. 



The small form (fig. 56) was found by Doherty on Pulo Dua, an 

 islet three miles east of Engano. 



A. MARTENSI Boettger. PI. 61, fig. 52. 



Shell large, sinistral [or dextral], very shortly rimate, broadly 

 conic-ovate, very solid; very lightly and densely striate, subopaque, 

 bright citron-yellow with wide white bands around the suture and rima- 

 tion and a single basal band on the penultimate (and next earlier) 

 whorls ; the last whorl with two wide olivaceous- green bands below the 

 periphery, the lower one double the width of the upper ; no dark 

 varices. Spire high conic, the right side more convex, apex pale 

 rose-white. Whorls 6, a little convex, separated by distinct, ap- 

 pressed sutures, the last whorl rather ventricose, not descending in 

 front, slightly over half the length of the shell. Aperture ear-shaped, 

 white inside and showing the two dark bands through, eight-fifteenths 

 the shell's length ; peristome white, thick, callous, evenly broadly ex- 

 panded and rejlexed throughout, the margins joined by a white 

 parietal callus ; left margin strongly and evenly curved, columella 

 vertical, callous, slightly twisted (Bttg.}. 



Alt. 49-53, diam. 27-30, aperture 26-28 mill. 



Borneo : Mt. Kina Balu (O. Staudinger & A. Bang Haas ; 

 Everett). 



A. martensi BTTG., Nachrbl. d. d. Mai. Ges. 1894, p. 66 FUL- 

 TON, Ann. Mag. N. H. (6), xvii, p. 71, pi. 7, f. 10. 



