462 
THE VOYAGE OF H.M.S. CHALLENGER. 
further stage of the type seen in Lecsna neo-zealanice. The sliorter bristles as usual have 
broader and shorter wings, and somewhat longer tips. 
The hooks (PI. XXVIIIa. fig. 9) are characteristic, presenting in profile six or seven 
visible teeth above the great fang. The mucro beneath the latter is in close proximity, 
an unusual condition in the series. The outline of the basal region differs from that of 
any known form, and the area of this part is comparatively large. A few faint 
transverse lines occur above the ventral margin. 
The mud in the intestine contains a few Diatoms, fragments of Radiolarians. Both 
are, however, rare amongst the fine 'muddy debris. 
The muddy wall of the tube, again, presents larger and more perfect Radiolarians of 
the trilobate kind formerly observed, arenaceous Foraminifera, fragments of sponge- 
spicules, and a few Diatoms. 
Lecena antarctica, n. sp. (PI. XLVIII. figs. 9, 10; PI. XXVIIIa. figs. 10, 11). 
Habitat. — Dredged at Station 156 (a little north of the Antarctic Sea), February 26, 
1874; lat. 62° 26' S., long. 95°44'E. ; depth, 1975 fathoms; surface temperature, 33° '0 ; 
sea-bottom. Diatom ooze. 
One or two fragments of a small form, the longest measuring 16 mm., and 1)eing 
rather more than 1 mm. in diameter at its widest part anteriorly. 
The body presents the usual appearance, with a horse-shoe shaped process, from 
which the tentacles proceed, above the mouth. It is difficult to estimate accurately the 
number of bristle-bundles, but they seem to correspond with the typical number, viz., 
ten. The longer forms (PI. XXYIIIa. fig. 10) have straight shafts and finely tapered 
tips, and the wings are well developed. The shorter bristles, one of which is represented 
at the lower part of the same figure, have broader wings and more attenuate tips. 
Four or five of each kind occur in a tuft. 
The hooks (PI, XXVIIIa. fig. 11) are comparatively small, four teeth, however, in 
favourable views being visible above the great fang. The exact nature of the outline 
beneath the latter is somewhat indefinite, but a slight projection (mucro) occurs a short 
distance below the base of the fang, and then a shallow^ excavation. The ventral margin 
is evenly convex. The hooks form a double row in front as in Lemia. 
The tip of the tail terminates in an expanded cup or funnel (PI. XLVIII. fig. 10), 
the anus being situated at the upper part of the latter, which in regard to the axis of the 
body is directed upward and forward. Thus the lower rim proceeds further backward 
than the anterior. 
Diatoms appear in the mud in the intestine, but only a small quantity could be examined. 
The tube is composed of a thin, translucent, chitinous lining coated wdth a friable 
