156 (iAZA, 



by a strong but narrow, equal, rounded, white pearly callus, which 

 almost disappears just at the upper corner, and which has a very 

 slight furrow round its margin ; it does not descend at all. 

 Inner lip — from the corner of the outer lip a very thin layer of 

 nacre spreads out a little way across the body, but then ceases 

 entirely. The pillar is spread out at its base as a confined, flattened, 

 unevenly inclined, semicircular, iridescent umbilical pad, from the 

 left corner of which the pillar proper projects, with a narrow but 

 rounded edge, twisted, straight, bending to the left, and advances 

 into a sharply angulated, and, as seen from behind, even nuicrouated 

 junction with the basal mouth-edge, to which the umbilical pad 

 curving round the back of the pillar also attains. The inside is 

 scored with the external sculpture, and is brilliantly ii-idescent. 

 The umbilical pad is defined by a narrow furrow, and in front by a 

 slightly tumid ridge, which is the least nacreous part of the whole 

 shell. Operculum is membranaceous, horny, yellowish, with about 

 six to seven turns, each strongly defined b}' a narrow line of thick- 

 ening, and sharply scored with minute oblique radiating lines. 



Alt. 0-65 in. ; diam. OvST in. Mouth, height 0-43, breadth 0*41 

 in. ( Watson.) 



Kandavu, Fiji, 610 fms. 



Gaza dcedala Watson, Journ. Linn. Soc. London, xiv, p. 602 ; 

 Challenger Gasteropoda, p. 93, t. 7, f. 12. 



G. suPERBA Ball. PI. 48, figs. 16, 17. 



Shell in general features recalling Gaza dsedala Watson, much 

 of whose description would apply with little change to this species. 

 Whorls eight, in the adult roundly shouldered below the suture, 

 rounded at the periphery, somewhat flattened on the base, deeply 

 and widely umbilicated, the umbilicus a little more than half 

 covered by a nacreous callus ; first two and a half wliorls trans- 

 parent, not nacreous, very obtuse, the nucleus not prominent ; the 

 next three and a half whorls smooth, except for faintest lines of 

 growth, glassy with the nacre sinning through ; the remainder of 

 the shell covered with delicate and distinct lines of growth, some- 

 times a little more pronounced near the suture and by revolving 

 lines almost too shallow to be called grooves, most pronjinent 

 on the periphery, evanescent on the flattened part of the base 

 and above near the suture ; on the last whorl these are about 0'5 

 mm. apart ; the region near the suture is almost smooth. Suture 



