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



Shell. — Conical, carinated, flat on the base, strong, opaque, covered with tubercles, 

 and coloured with grey and piuk. Sculpture : There are eight spiral rows of small round 

 tubercles on each whorl. The tubercles on the first two rows are larger than the others ; 

 these, as well as the next three rows, are parted by distinct depressions ; the lowest three 

 rows are much closer together, but project a little, especially the centre and largest row 

 of the three. On the base there are about nine less strongly tubercled spiral threads, 

 with feebler threads between, these intermediate threads becoming feebler towards the 

 centre. The tubercles are smooth and polished, but the whole intervening surface is 

 sharply fretted with fine oblique puckerings. Colour white, beautifully flecked above 

 with greyish-purple blotches, and closely spotted with purplish pink on the base. Spire 

 high and sharp-pointed, its concavely conical slope being slightly broken at the sutures 

 by the projection of the two superior rows of tubercles. Whorls about 10, flat and 

 of very regular increase. Suture slight, but distinct, being defined by the slight carinal 

 spiral above, and the double row of larger tubercles below. Mouth rather small, square, 

 and very oblique. Outer Up sharp but strong. Inner lip strengthened internally by a 

 buttress of porcellanous nacre, which ends abruptly towards the point of the pillar, forming 

 a tooth. The pillar, bevelled off to a sharp edge, is pressed back on the umbilicus, which 

 it completely closes, leaving only a central depression and a post-columellar furrow. 

 Operculum thin, yellow, normal. H. 0'64 in. B. 0'58, least 0"52. Penultimate whorl, 

 0-18. Mouth, height 0-42, breadth 0-3. 



This species very much resembles Trochus dccoratus, Phil., but that species is more highly 

 narrowly conical, is flatter on the base, and the whole system of spirals is different. In Trochus 

 dccoratus also the earlier whorls are simply spiralled ; here the spirals are cross-hatched. Trochus 

 nobilis, Phil., is much larger, is flatter on the base, and is not so closely spiralled. Trochus cughjptus, 

 Ad., has the whorls much rounder. 



16. Trochus (Ziziphinus) stephanephorus,' n. sp. (PI. XVII. fig. 1). 



Station 201. October 26, 1874. Lat. 7° 3' K, long. 121° 48' E. Philippines. 82 

 to 102 fathoms. Stones, gravel. 



Shell. — High, conical, tubercularly carinate and lirate, ruddy, with a coronated apex, 

 glossy smoothish flatly conical whitish base, and a large quadrangular mouth. Sculp- 

 ture : Longitudinals — the whole surface is obliquely scored with broadish well-parted 

 little raised rounded striae on the lines of growth, on the base these are feebler and less 

 regular. Spirals — on each whorl there are about 7 strongish equal threads, which are 

 somewhat sparsely dotted with low flat tubercles, whose greatest breadth is in the height 



1 This word follows the form of the island's name as written on the boxes sent me. 



2 onpavripig');, coronated. 



