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



tracted below this point, tumid on the base, drawn in at the pillar, with a small, short, 

 sharp-pointed snout. Suture very strong and distinct, from the concave curve of the 

 whorl above it and the horizontal tabulation of the collar below. Mouth largish, angularly 

 pear-shaped. Outer lip thin, angulated, straight and horizontal above, convex and patulous 

 below the angle, drawn in at the snout ; it retreats at once on leaving the body to form 

 the rather deep, narrow, rounded sinus which occupies the shoulder, but whose apex 

 occurs at the carina ; below this it descends very little, but runs out into a very convex 

 curved edge, whose prominence is greatly increased by the rapidity and extent of the 

 retreat of the lip-edge at the snout. Inner lip is narrowly excavated in the substance of 

 the shell on the body and down the pillar ; it has a convex contour across the body, at 

 the junction of which and the pillar is a strong but rounded angle ; the pillar is short, 

 strong, conical, obliquely truncated in front, with a sharp, rounded, twisted edge. H. 

 0-25 in. B. 0-16. Penultimate whorl, height 0'04. Mouth, height 0'14, breadth 0*09. 



The largest specimen of this species seems somewhat immature. I have called it simply a 

 Pleurotoma, because its sinus occurs at the peripheral keel, but its apex is not that of a simple 

 Pleurotoma. 



8. Pleurotoma xanthophaes, 1 n. sp. (PI. XXVI. fig. 1). 



Station 163b. June 3, 1874. Lat. 33° 51' 15" S., long. 151° 22' 15" E. Port 

 Jackson, Sydney. 30 to 35 fathoms. Hard ground. 



Shell. — High, narrow, fusiform, subscalar, bicarinated, tubercled, fulvous, with brown 

 specks between the carinal tubercles. Sculpture : Longitudinals — there are rough lines 

 of growth. Spirals — the whole surface is covered with very unequal threads ; imme- 

 diately below the suture is a broadish thread, puckered by the lines of growth ; below 

 this on the shoulder of the shell there are 3 feeble threads rather widely and quite shal- 

 lowly parted ; the corner of the shoulder has a strongish rounded keel cut into white 

 blunt tubercles, between which are chestnut spots ; below this keel is a broad and some- 

 what constricted furrow in which are some (3 to 6) feeble threads ; the lower side of the 

 furrow is formed by another keel also tubercled and speckled, but weaker than the upper 

 keel. Between these two keels the shell is cylindrical ; from this point it begins to con- 

 tract, has one feeble thread, then plainly within the base 2 strongish threads, which are 

 subtubercled ; below this on the front of the base and on the pillar are about 10 threads ; 

 the point of the pillar has no threads, but is very rough. Colour fulvous, with whitish 

 and chestnut specks; the point of the snout is white. Spire high, narrow, conical, slopingly 

 scalar. Apex coronated (?) ; it is somewhat rubbed, but seems to consist of 3 to 4 whorls. 

 Wliorls 7, exclusive of those of the apex ; they are bicarinated, constricted above and 

 1 ^rjivOtxfiar,;, with a chestnut gleam, the colour between the tubercles. 



