570 THE VOYAGE OF H.M.S. CHALLENGER. 



phery ; on the earlier whorls they extend from suture to suture ; they are parted by open, 

 round, shallow, rather broader furrows. Spirals — the whole surface is covered with round 

 threads and similar furrows ; of these there are about eight on the penultimate whorl. 

 Colour pure white, only the apical style has a tinge of ruddiness. Apex : the style is 

 nearly cylindrical, and consists of three very small, short, smooth whorls, of which the 

 middle one at its origin projects slightly beyond the next. Spire rather high, with conical 

 but slightly convex profile lines. Whorls 5, besides those of the apex ; they are rather 

 short and broad, convex, with a very slight angulation in the middle. Suture angularly 

 impressed and strong. Mouth a perfect oval, with the faintest possible gutter at the pillar 

 point. Outer lip thin, arched, with a very slight flattening of the curve ; it is patulous 

 on the base, especially near the pillar point. Inner lip concave, with a slightly 

 straightened but oblique line on the pillar, whose edge is sharp and short, being obliquely 

 cut off before it reaches the base. H. 0-09 in. B. 0'049. Mouth, height 0'033, breadth 

 0-028. 



This shell is a good deal like a delicate Eissoa, bat the form of the inner lip and pillar, and the 

 style-like apex, connect it with the Stiliferinas. 



6. Alaba (Stiliferina) sulcata, n. sp. (PL XLII. fig. 7). 



Station 187. September 9, 1874. Lat. 10° 36' S., long. 141° 55' E. Off Cape 

 York, North-east Australia. 6 fathoms. Coral mud. 



Shell. — Ovate, pointed at either end, white, spirally striated on the base, with a tumid 

 body, short rounded whorls, a produced and furrowed base, a conical spire, a small but 

 scarcely style-bearing apex, and an ovate subfusiform mouth. Sculpture : Longitudinals — 

 there are many small faint rounded convolutions of the surface ; towards the outer lip 

 some very fine, narrow, feebly raised, rounded riblets begin to appear. Spirals — round 

 the top of the last whorl, close up to the suture, runs a very narrow shallow furrow : the 

 middle of the whorl is smooth ; round the bottom of the penultimate whorl one or two 

 very faint spirals may be detected ; just at the periphery, where the insertion of the outer 

 lip occurs, a series begins of five or six shallow little furrows, 1 with barely rounded and 

 broader threads between them ; they rather increase in distinctness for about half way 

 across the base and then cease, the middle round the pillar being smooth. Colour 

 hyaline. Apex : there is hardly a style, but the first whorl and a half stand up a very little ; 

 the extreme tip is small and dome-shaped. Spire conical, short. Whorls 5 ; the upper 

 ones are small and rounded, the last is a little flattened on the side slopes, has a very 

 feeble subangulation at the periphery and a rounded base, produced by the pillar into a 

 rather long and small point. Suture impressed, horizontal. Mouth ovate, but run out 



1 It is from this feature that the name is taken. 



