MOLLUSCA OF THE ' CHALLENGES ' EXPEDITION. 419 



which does not really exist in the form of the whorls themselves : 

 there is a very slight contraction towards the lower suture. The 

 last whorl contracts slightly from the keel to the edge of the 

 base, and from that point rapidly to the small, narrow, straight, 

 and direct snout. Suture coarse, slightly impressed, and well 

 defined by the band below it. Mouth narrowly oval, pointed 

 above, with an oblique, short, rather open and gradually con- 

 tracted canal in front. Outer lip a rather depressed convex curve, 

 a little concave at the top and flattened toward the point : on 

 leaving the body it retreats at once, forming a shallow, blunt V- 

 shaped sinus, from the lower side of which, with little of angula- 

 tion, it advances very straight to the edge of the canal, whence it 

 slowly curves backward round the open point of the snout. Inner 

 lip spreads as a very narrow porcellaneous glaze ; it runs very 

 obliquely to the base of the shortish narrow pillar, below which 

 point it is a very little hollowed. The point of the pillar is cut 

 off with a very slight obliquity, and has a blunt and very slightly 

 twisted edge. Operculum small, oval, smooth, with hair-like 

 strise, apex terminal, colour pale brownish yellow. H. 0*5. 

 B. 0-23. Penultimate whorl, height 0*1. Mouth, height 024, 

 breadth 012. 



The blunt apex, the ribs, and coarse spirals of this species sug- 

 gest some faint affinity with the P. nivalis, Loven, group ; but it 

 is very remote. 



22. Pleueotoma (Dkillia) spicea, n. sp. 



St. 122. September 10, 1873. Lat. 9° 5' S., long. 34° 50' W. 

 Off Pernambuco. 350 fms. Mud. 



Shell. — Short and broad, biconical, scalar, angulated, without 

 ribs, but with tubercles at the angle, and feeble spiral threads on 

 the base ; the snout is small and lop-sided. Sculpture. Longitu- 

 dinals — there are none but very fine, unequal, hair-like lines of 

 growth. Spirals — immediately below the suture is a minute 

 collar of very small, high, round, remote tubercles, whose sutural 

 surface at right angles to the axis is perfectly flat ; this collar is 

 strongest on the earlier whorls ; below this is a sloping, flat, or 

 slightly concave shoulder. A little above the middle of the 

 whorls is a rectangular angulation beset with small, remote, 

 slightly elongated, sharpish tubercles, which give the appear- 

 ance of a sharply expressed keel ; of these tubercles there are about 



