446 EEV. E. BOOG WATSON ON THE 



a thin sharp margin along the canal. H. 0*51. B. 0"28. Penul- 

 timate whorl, height 0*13. Mouth, height 0'32, breadth 014. 



This species is more like Thesbia nana, Lov., than any thing 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. 



44. Pleueotoma (Thesbia) coepttlenta, n. sp. 

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

 Royal Sound, Kerguelen. 28 fms. Mud. 



Shell. — Thin, oval, spirally striated, with a tumid body- whorl, 

 and a rather high, subscalar, small-pointed, round-whorled, 

 shallow-sutured, conical spire, an obliquely conical base, and a 

 slight snout. Sculpture. Longitudinals — slight hair-like lines of 

 growth. Spirals — the subsutural sinus-area is very slightly con- 

 cave, and below it is a slight carinal angulation ; the whole sur- 

 face 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 contracting 

 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 trun- 

 cate 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 (w^hich forms a regular concave 

 curve) out to the thin, twisted, obliquely truncate edge of the 

 pillar ; this edge runs out beyond the thin labial pad, and forms a 

 sharp margin along the canal. H. 055. E. 0*31. Penultimate 

 whorl, height 01. Mouth, height 0*3, breadth 019. 



Compared with P. (Thesbia) translucida, Wats., this has a rather 

 higher and narrower spire, the suture is more oblique, and the 

 last whorl, besides being much shorter, is more tumid above and 

 less so below. 



