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



number) in the middle of the body are broadest ; those on the snout are the most 

 prominent, especially the highest three ; of the group on the body, the highest which 

 comes in below the sinus-area forms a very slight keel to the whorls. Colour buff. Spire 

 subscalar, high, conical. Apex consists of \\ embryonic whorls, which rise regularly to a 

 high, fine, rounded point, the extreme tip of which is quite prominent. Whorls 7, of 

 regular increase, high and rather narrow, very slightly carinated, convex ; the last is long 

 and narrow, nearly cylindrical in the middle ; on the right side the base is scarcely 

 contracted ; but on the left side it is cut off with a long, oblique, and very considerable 

 truncation, and is in this way very lop-sided. Suture not deep, but distinct and im- 

 pressed. Mouth long and narrow, with nearly parallel sides ; the short open canal is of 

 the same width and direction as the mouth itself, and ends in a rather deep nick ; the 

 sinus above is about half the width of the mouth, from which it turns off through the 

 thick lip very obliquely, and is funnel-shaped. Outer lip in direction oblique and almost 

 straight, a very little inflected, thick, its front face roundly bevelled off to the inner side, 

 and its two sides parallel ; it is strengthened by a strong external rounded varix, which 

 extends to the front of the very short snout but not to the pillar ; internally there is a 

 slight pad faintly scored by very obscure teeth, but terminating in a single, small, rounded, 

 and rather prominent tubercle on the lower side of the sinus. Inner lip very narrow and 

 thin, but with a thickened pad between the sinus and the body-whorl ; its direction is 

 oblique, a little concave above; it is very straight on the pillar. H. 0'152 in. B. 0*06. 

 Penultimate whorl, height 0'028. Mouth, height 0-078, breadth 0-019. 



This species resembles a good deal a very small and refined Pleurotoma rugulosa, Phil., having 

 the same lop-sided base ; but that species has the right side of the base somewhat more obliquely 

 truncated ; so that there is much less of inequality between the two sides than in the Challenger 

 species, which is also slimmer, has the sculpture both of ribs and spirals very much finer, the apex 

 much smaller and higher, the suture less deep, and the nick of the canal in front very much more 

 distinct. 



70. Pleurotoma (Mangelia) levukensis, Watson (PL XXIII. fig. 7). 



Pleurotoma {Mangelia) levukensis, Watson, Prelim. Report, pt. 9, Journ. Linn. Soc. Lond., vol. xv. 



p. 432. 



July 29, 1874. Levuka, Fiji. 12 fathoms. 



This species extremely resembles Pleurotoma septangular is, Mont., in general appearance and in 

 sculpture, both as regards ribs and the fine spiral striae. In form it is smaller, narrower, and much 

 more cylindrical, the body-whorl is similarly tumid ; but it and the mouth still more are shorter ; the 

 penultimate whorl is very much smaller and especially is narrower ; while the upper whorls are 

 broader, and the apex very much broader and blunter. The specimen is in too bad condition for 

 detailed description. 



H. 0-22 in. B. 01. Penultimate whorl, height 0-04. Mouth, height 0-09, breadth 0-038. 



