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



The solitary specimen of this species is so badly broken that the measurements and the descrip- 

 tion of all about the mouth is impossible ; but the whole character of the shell is so strongly marked 

 that the recognition of the species will always be easy. It is something like Fusus (Siphonorbis) 

 dalli, Friele (not Watson), but is a bigger shell, with a much larger and more flatly rounded apex, 

 the whorls are not nearly so convex, the shoulder is much more sloping, the two large threads which 

 form the carina are both stronger and more prominent than any on that species, and the finer spirals 

 are very much more frequent. The "Porcupine" Expedition in 1870 got three young specimens of 

 this species at Stations 16 and 17, close to Setubal, in from 740 to 1095 fathoms. 



22. Fusus (Sipho) libratus, Watson (PI. XII. fig. 8). 



Fusus (Neptunea) dalli, Watson, Prelim. Report, pt. 14, Journ. Linn. Soc. Lond., vol. xvi. p. 379. 



Station 173. July 24, 1874. Lat. 19° 9' S., long. 179° 42' E. Off Matuku, Fiji. 

 315 fathoms. Coral mud. 



Shell. — Thin, porcellanous, pale ruddyish yellow, fusiform, long, of nearly equal 

 size above and below the periphery, finely ribbed and spiralled, with confessed aud 

 constricted whorls, and a club-shaped mouth. Sculpture: Longitudiuals — the whorls 

 are crossed by narrow little ribs and furrows, of which there are about 11 on the 

 upper whorls and 19 to 20 on the penultimate, becoming increasingly feeble as they 

 approach the mouth ; they harmonise completely with the course of the dense, 

 clear, and sharp hair-like lines of growth. Spirals — there are narrow, prominent spiral 

 threads, of which two near the bottom of the whorls are somewhat stronger than the 

 others ; the furrow which parts them is also a little wider and deeper than the rest ; 

 below this is a small but rather sudden constriction of the whorls into the suture ; the 

 spirals in crossing the longitudinal ribs are thrown out into blunt white linear points ; 

 the spirals on the base and snout are more regular and equal than the others. Colour a 

 pale ruddyish yellow, with a fine roughened surface. Spire high and conical. Apex 

 broken, but apparently very small, sharp, and smooth. Whorls, 8 remain ; probably the 

 broken embryonic apex consisted of two more; they are convex, with a slight slow 

 contraction above and a small sudden constriction below ; the last is small, long, with 

 rounded outlines, and produced into a long, rather lop-sided and slightly twisted snout. 

 Suture fine, sharp, impressed. Mouth long, club-shaped, being oblong, pointed above, and 

 produced in front into a longish canal. Outer lip thin, with a slight, white, internal 

 varix, not much arched, patulous in front, where its line is concave, and then straight 

 along the canal. Inner lip short and scarcely convex on the body, hollowed at the base 

 of the pillar, which is narrow, straight, and cut off in front, on a long, slightly oblique, 

 and somewhat twisted line ; the glazing which edges it is very thin and narrow. H. 

 1-27 in. B. 0"5. Penultimate whorl, height 0'2. Mouth, height 07, breadth 0-24. 



