REPORT ON THE GASTEROPODA. 353 



little bent down on one side. Whorls 10 in all, of regular proportions and uniform increase ; 

 they are conical above and cylindrical below the keel ; the last whorl is slightly tumid, and 

 contracts very gradually to a long and small snout. Suture extremely minute, as each whorl 

 laps up on the one above it. Mouth oblong, pointed above, and drawn out into a long 

 narrow canal below. Outer lip is pretty regularly arched from the body to the canal, 

 from which point it is drawn out rather straight ; its edge advances in the middle very 

 prominently ; above this it forms a high shoulder, between which and the body-whorl lies 

 the deep, rounded, and very wide-mouthed sinus ; towards the front of the mouth the 

 edge runs straight, then retreats, so as to form a broad, slight, small sinus at the top of 

 the canal, and then runs straight. Inner lip : there is a thin glaze excavated slightly in 

 the substance of the shell. The pillar is long, narrow, and fine-pointed, with a slight 

 swelling coiling round its base, where its junction with the body is but slightly concave. 

 H. 0'85 in. B. 0*35. Penultimate whorl, height 0-16. Mouth, height 0*43, breadth 0-2. 



This species has a considerable likeness to Plcurotoma torquatum, Phil. ; but that is a larger, 

 broader, stumpier form, has the individual whorls shorter, more strongly keeled, ornamented with 

 little rounded tubercles instead of with narrow, pinched-up, very oblique riblets ; has also a much 

 more horizontal suture ; the whorls, too, are not cylindrical, but contract from the keel to the lower 

 suture ; the base is much more drawn in, and the pillar much shorter ; the whole texture also and 

 sculpture is much stronger than in the Challenger species. 



The specimens from Station 24 and Station 85 are markedly stumpier in form, more sharply 

 keeled, and with a higher shoulder and a rather smaller embryonic apex ; but the whole details of 

 sculpture are identical. 



7. Clathurella pachia 1 (Watson), (PL XIX. fig. 5). 



Pleurotoma (Defrancia) pachia, Watson, Prelim. Report, pt. 10, Journ. Linn. Soc. Lond., vol. xv. 



p. 460. 



Station 24. March 25, 1873. Lat. 18° 38' 30" N., long. 65° 5' 30" W. North of 

 Gulebra Island, West Indies. 390 fathoms. Pteropod ooze. 



Shell. — Ovate, white, smooth, of rounded outlines, with a rather high, small, and 

 sharp-pointed apex, a swollen body-whorl, and a rounded base produced into a small, 

 broad, one-sided snout. Sculpture : Longitudinals — there are only very fine hair-like 

 lines of growth, of which here and there at regular intervals one becomes much more 

 strongly marked than the others. Spirals — the whole surface is sparsely scored with very 

 shallow, scratched-out, narrow furrows, parted by flat intervals of from two to six times 

 their breadth ; in the sinus-area they are a little closer than elsewhere ; on the snout they 

 gradually broaden till their intervals assume the form of slight rounded threads. Colour 

 like a shaving of ivory, from its thinness, gloss, and colour. The apex is buff. Spire 



1 Kayjj;, fat. 

 (tool, chall. exp. — part xlii. — 1885.) Tt 45 



