232 GIBBULA. 



A globose-conoid species, with two strong rounded keels, the 

 whole surface covered with fine spiral striae. One of the specimens 

 before me from BRAZIER has no color markings. 



G. OPPRESSA Hutton. PI. 40, figs. 4, 5. 



Shell small, imperforate (or with a shallow " false umbilicus "), 

 conical, somewhat solid, lusterless, dark olive-brown or greenish, 

 minutely tessellated all over with a slightly darker shade of the 

 same hue (scarcely visible unless the shell be wetted); whorls about 

 5, convex, those of the spire keeled in the middle, body-whorl 

 biangular, base rather flattened ; entire surface closely finely spirally 

 striate, the striae of base becoming coarser toward the axis ; aperture 

 oblique, quadrangular, smooth within and brilliantly iridescent, the 

 nacre dark green with red reflections ; lip slightly thickened by a 

 narrow opaque margin within, not crenulated ; columella oblique, 

 straight, long, inserted in the center of the base; umbilicus filled 

 with callus, leaving only a slight pit. Alt. 5, diam. 6 mill. 



Auckland, N. Z. 



G. oppressa HUTTON, Journ. de Conchyl. 1878, p. 34 ; Proc, Linn- 

 Soc. N. S. W. 1884, p. 364; Trans. N. Z. Inst. xv, t. 14, f. M. 

 (dentition). 



My description and figure are drawn from a specimen received 

 from Professor HUTTON. The imperforate axis separates this form 

 from the preceding biangulate Australian Gibbula. 



G. PRASINA Garrett. PL 40, figs. 14, 15. 



Shell minute, perforated, globose-depressed, rather thin, scarcely 

 shining, light olive-green, mottled closely with dark greenish; the 

 whole surface, save a circum-umbilical tract, often uniform blackish- 

 green ; spire very short, formed of 4 very rapidly widening whorls 

 separated by well-marked sutures; the whorls spirally lirate except 

 on the base, the lirse slightly crenulated by indistinct oblique 

 growth marks; aperture very large, very oblique, rounded, the 

 extremities of peristome nearly joining, connected by a short parietal 

 callous ; columella and basal margins equally curved, simple and 

 smooth within ; umbilicus quite narrow. 



Alt. 2*, diam. 3i mill. ; alt. 3, diam. 4 mill. 



Viti Is. 



Gibbula prasina GARRETT, Proc. Cal. Acad. Sci. iv, p. 202. 



