230 ON THE MOLLTJSCA OE THE ' CHALLENGER ' EXPEDITION. 



white, with a few faint, suffused, small, ruddy blotches, chiefly on 

 the spiral threads, but sometimes continuously curvedly longitu- 

 dinal. The upper part of the spire is uniform white or ruddy. 

 Spire high, narrow, and sharp, with straight profile lines. Apex 

 glossy, porcellanous. The last 2| whorls contract rather sud- 

 denly to the very small, sharply rounded, and prominent point. 

 Whorls 16, perfectly flat, with a slight tendency to angular con- 

 vexity in the earlier ones, of very regular and gradual increase ; 

 the last is bluntly angulated on the edge of the base, which is 

 conical and slightly convex. Suture linear and very slightly im- 

 pressed, defined by the slight swelling of the base of the superior 

 whorl. Mouth small, square-shaped, but higher than broad. 

 Outer lip advances somewhat where it springs from the base, and is 

 here a little drawn in from the edge ; it advances with a slight curve, 

 and is a little patulous toward the outer lower corner, is flat across 

 the base, and advances rather beyond the point of the pillar, where 

 there is a slight open canal. The generic sinus of the outer lip is 

 semicircular. Inner lip: a flat, but distinct, porcellanous white 

 callus crosses the body-whorl and spreads, but with decreasing 

 thickness, round the base of the pillar. The pillar is narrow, 

 rounded, and perpendicular. H. 13. B. 0*3, lea«t 029. Penul- 

 timate whorl, height 0*18. Mouth, height 019, breadth 0"16. 



T. Gunnii,l&ve., from" V. Diemens Land," has a much coarser 

 spire, a deeper suture, and the angle of the base more rounded. 

 In general aspect T. declivis, Ad. & Eve., is not unlike, but 

 the ' Challenger ' species is of more rapid increase, has not 

 the same projection above the suture, and the whole details of 

 sculpture are different ; but the specimens of T. declivis in the 

 British Museum from the " China Seas " are in very bad condition. 

 It has some resemblance to T. monilifera, Ad. & Eve., " China 

 Seas ; " but is a thinner shell, not so fine toward the apex, and the 

 upper whorls want the angulation of that species. 



