254 EEV. E. BOOG WATSON ON THE 



separated distinctly from the pad at the upper angle of the 

 mouth ; the radiating wrinkles on the upper whorls are much 

 stronger and more regular, and the embryonic apex is very much 

 smaller, sharper, and more distinctly denned. JV. vittata, Gin., 

 which in other respects is quite different, has the same pillared 

 umbilicus with carinated edge, which is, indeed, not unusual in the 

 genus. 



2. Nattca attpha, n. sp. (arvcpos, unpretending.) 



St. 188. Sept. 10, 1874. Lat. 9° 59' S., long. 139°42' E. "W. 

 of Cape York, S.W. of Papua. 28 fms. Mud. 



Shell. — Depressedly conically globose, umbilicate, spire little ex- 

 serted, smooth, of a pale, faintly ruddyisli white, with an obscure, 

 broad, rusty band above the periphery. Sculpture. Longitudi- 

 nals — there are many slight, hair-like, faintly sinuous lines of 

 growth, which towards the suture are gathered into puckerings, and 

 become stronger towards the umbilicus. Spirals — the whole sur- 

 face is very faintly superficially and unequally furrowed, and is 

 also slightly microscopically and regularly scratched. Within the 

 umbilicus, but finally running out with a twist to the point of the 

 pillar, is an indistinct and blunt circumumbilical carina. Colour 

 ivory-white, with a faint tinge of buff, hardly glossy ; from the peri- 

 phery to within one third of the whole distance to the suture there 

 extends a broad, pale ruddyish-purple band, whose colour deepens 

 on the spire to the apex. Epidermis : none visible. Spire short, 

 the separate whorls being little prominent. Apex rather large and 

 tumid, but depressed. Whorls 4|, the first 1| of which are em- 

 bryonic; they are well rounded and tumid, of slow and regular 

 increase. Suture nearly horizontal, but more oblique towards 

 the mouth, not deep, but slightly channelled. Mouth slightly 

 oblique, nearly semicircular, but a little pointed above, about 

 three fourths of the total height, open, slightly angulated at the 

 umbilical carina, pure white within, but with a very faint tinge of 

 rust at the band. Outer lip open, thickish and blunt, a little 

 flattened above where it leaves the body -whorl ; its curve is very 

 equable throughout. Inner lip porcellanous white, straight, 

 little oblique, reverted, thickish, with a minute ledge within the 

 edge of the mouth ; its upper corner has a largish, slightly pro- 

 jecting pad, with a slight shallow channel between it and the edge 

 of the outer lip ; below this pad the inner lip slightly retreats, 

 but at the large white pad which fills the upper part of the urn- 



