MOLLUSCA OP THE ' CHALLENGER ' EXPEDITION. 225 



St. 149 d. January 20, 1874. Lat. 49° 28 r 8., long. 70° 13' E. 

 Royal Sound, Kerguelen. 28 fms. Mud. 



Shell. — Conical, with rounded whorls, basal angle, and base, a 

 deeply impressed suture, a fine tapering point, a round mouth, 

 two strong spiral threads on each whorl, a very distinct yellow 

 epidermis. Sculpture. Longitudinals — there are many fine, faint, 

 close-set, semicircular lines of growth preserving the curve of the 

 labral sinus. Spirals — there are two strong rounded threads about 

 one third of the whorl's height apart ; they are nearly equally 

 prominent and angulate the whorls, strongly in the earlier, less 

 so in the later stages of growth. Between these is a shallow open 

 furrow, in the middle of which is a fine narrow thread ; one or 

 two similar threads lie remotely on the upper slope of the whorl, 

 where it contracts gradually into the suture ; one spiral thread of 

 the same kind lies in the open furrow, which abruptly contracts 

 the bottom of the whorl into the suture. The edge of the base is 

 contracted and rounded, with a strong spiral thread which meets 

 the outer lip ; the base is smooth but for the sharp and very 

 strong generic spiral lines which cover the whole surface and are 

 not microscopic, being easily seen with a lens. Colour porcella- 

 nous white under the straw-yellow epidermis. Spire high and 

 conical ; but its profile lines are deeply interrupted by the strongly 

 contracted sutures. Apex drawn out to a fine, prominent, but 

 rounded and slightly tumid point. Whorls 12, well rounded, with 

 a slight double carination ; the two carinating threads lie nearer 

 the bottom of the whorl ; they are separated by a shallow furrow : 

 beneath the under one the whorl is sharply contracted into the 

 suture, while from the upper keel the whorl slopes by a regular 

 curve into the superior suture. The first 6 or 7 whorls are 

 markedly smaller than those which follow. The base is round and 

 rather prominent. Suture fine, but strongly marked by the con- 

 traction above and below. Mouth rather small, round. Outer 

 Up slightly advancing on the edge of the base, somewhat open, 

 very slightly angulated at the lower outer corner, a very little flat- 

 tened on the base, patulous, and a little angulated at the point of 

 the pillar. Inner lip crosses the body and coils round the base 

 of the pillar as a very thin glaze. Pillar a little oblique, curved, 

 patulous, sharp, and with a distinct twist on the edge. Epi- 

 dermis very distinct, thin, membranaceous, and marked with the 

 fine generic spiral lines ; it is very caducous. In drying it 

 seems to have risen through contraction, so as to remain attached 



