REPORT ON THE GASTEROPODA. 331 



whorl the form is cylindrical, with a very slight contraction into the lower suture. The 

 whorls increase regularly, but rapidly ; the last is large and tumid, with a protracted 

 rounded base cut off on the left by an oblique, barely concave line. There is scarcely 

 any snout, and the shell is truncated obliquely towards the point of the pillar, which 

 projects in a rectangular prominence. Suture linear, impressed. Mouth very large, lop- 

 sidedly oval, pointed above and below. Outer Up a semicircular curve in both planes, 

 leaving a shallow, wide, shortly rounded sinus between the lip-edge and the body. Inner 

 lip : a thin, narrow pad stretches very regularly along its whole length (which forms a 

 very regular concave curve) out to the thin, twisted, obliquely truncated edge of the 

 pillar : this edge runs out beyond the labial pad, and forms a thin sharp margin along 

 the canal. H. 0-51 in. B. 0*28. Penultimate whorl, height 0-13. Mouth, height 032, 

 breadth 0-14. 



This species is more like Plcurotoma (Thesbia) nana, Lov., than anything else I know; but 

 besides being very much larger, it has the body-whorl very much longer and more tumid, and 

 the spire very much stumpier. 



61. Pleurotoma (Tliesbia) corpulenta, Watson (PI. XXV. fig. 8). 



Pleurotoma (Thesbia) corpulenta, Watson, Prelim. Report, pt. 9, Journ. Linn. Soc. Lond., vol. xv. 



p. 446. 



Station 149d. January 20, 1874. Lat. 49° 28' S., long. 70° 13' E. Royal Sound, 

 Kerguelen. 28 fathoms. Volcanic mud. 



Shell. — Thin, oval, spirally striated, with a tumid body-whorl, aud a rather high, sub- 

 scalar, small-pointed, round-whorled, shallow-sutured, conical spire, an obliquely conical 

 base, and a slight square-cut snout. Sculpture : Longitudinals — there are slight hair-like 

 lines of growth. Spirals — the subsutural sinus-area is very faintly concave, and below it 

 is a slight carinal angulation ; the whole surface is covered by fine flatly rounded threads, 

 which are stronger and more remote on the penultimate than on the last whorl. Colour 

 white. Spire rather high, conical, subscalar. Apex small, conical, rounded, with the 

 extreme tip flattened down. Whorls 6, rounded, tumid in the middle, and very slightly 

 contracted below into the suture ; they increase regularly, but rather rapidly ; the last is 

 large, rather tumid at the shoulder, and contracts with considerable equality on either 

 side to a shortly produced conical base, ending in a small but broadish snout. Suture 

 broadly impressed. Mouth large, oval, pointed above, and truncate below at the point of 

 the very short canal. Outer lip : a semicircular curve in both its planes : its edge forms 

 a rather high shoulder, between which and the body lies the rather deep, funnel-shaped, 

 rounded sinus. Inner lip: a thin narrow pad stretches along its whole length (which 



