MOLLUSCA OE THE ' CHALLENGER ? EXPEDITION. 271 



earlier whorls follow continuously, but rather lag behind their 

 true place; on the body-whorl they are dislocated by being 

 thrown considerably in front of it ; the last one does not extend 

 to the snout ; there are minute, not very continuous, uneven, 

 longitudinal threads over the whole surface. Spirals — about a 

 third of its height below the suture the last whorl is carinated at 

 its periphery by a row of sharp, prominent, distant, round-based 

 tubercles, which are hardly continuous nor set on a cord ; on the 

 spire this row nearly bisects the whorls, but is a little inferior ; 

 between this row and the suture there are placed alternately 3 fine 

 tubercled threads and 2 tnbercled cords, of which latter the upper 

 is the stronger ; its tubercles and those of the thread above it 

 at the suture tend to coalesce ; less than halfway below the peri- 

 phery there is a row of smaller, less prominent, more numerous, 

 pointed tubercles set on a cord ; halfway between these two rows 

 is a cord with close-set rounded tubercles having two threads 

 below it and a thread and a fine tubercled cord above it, which 

 last lies on the bases of the tubercles forming the peripheral 

 carination. On the base are four tubercled cords, the first and 

 second of which have a fine tubercled thread above them, and the 

 fourth a similar thread below it defining the base of the pillar; 

 on the pillar there are 6 cords more or less tubercled, of which 3 

 cover the snout, two are on the underside, and one at the edge : 

 there is little difference in the strength or arrangement of the 

 spiral cords or tubercles above or below the periphery ; they all 

 rise into very considerable prominence and sharpness in crossing 

 the varices. The whole shell is covered by minute threads, which 

 form knots where they cross the rather weaker longitudinal 

 threads, giving the surface somewhat of the texture of a fine file. 

 Colour dead white, with a superficial ruddy-yellow tinge, which has 

 a few lines and patches of deeper hue and a few spots of chest- 

 nut. Epidermis: only a few traces of a very thin, smooth, mem- 

 branaceous skin remain. Spire high, narrow, and small, conical, 

 somewhat scalar from the infrasutural shoulder, whose angularity 

 breaks the conical outline. Apex consists of 3 polished, turbi- 

 nated, ochraceous whorls whose tip is immersed. Whorls 8 to 9 in 

 all, with a sloping flat shoulder, a carinated periphery, and a slight 

 straight contraction from this point to the suture ; the rounded base 

 contracts quickly on the left, bearing on this side a long, prominent, 

 bent and twisted pillar, which is lost on the right side by the out- 



