88 
THE VOYAGE OF H.M.S. CHALLENGER. 
spinous rows are so closely arranged (PI. Xa. fig. 8) that the whole surface is more or less 
hispid. The tip is acute and very slightly curved, no trace of a secondary process 
being visible in any. 
The structure of the head is peculiar, and the bristles differ from those of Lagisca, 
though the simple tips of such as Lagisca jeffreysii are closely allied. A new genus 
will probably be necessary for its reception, after a complete example is obtained. 
The intestine contained fragments of minute Crustacea, the stomachs of which seem 
to have been loaded with Diatoms, minute Foraminifera, and other organisms. 
In transverse section the first feature is the thinness of the cuticle, which forms a 
mere fi lm over the attenuated hypoderm in the median ventral line, where it usually 
is conspicuous. These layers thus form a very thin investment outside the nerve-trunks, 
which are of considerable size. The proboscis seems to be proportionally large in 
comparison with the thin walls of the body. 
Lagisca crosetensis, n. sp. (PI. VIII. fig. 6 ; PI. XIII. fig. 2 ; PI. XYIII. fig. 7 ; 
PI. XIa. figs. 4-6). 
Habitat . — Two specimens were procured by the trawl at Station 147 (near the 
Crozet Islands), December 30, 1873; lat. 46° 16' S., long. 48° 27' E. ; depth, 1600 
fathoms ; bottom temperature 34°‘2, surface 41°‘0; Diatom ooze. 
The form is characterised by the whitish papillose scales, the long palpi, the rapid 
diminution of the body posteriorly, and the length of the dorsal bristles. Many of the 
feet had been thrown off, probably on immersion in spirit, so that it is in all likelihood 
active and irritable. 
The head has two rather distinct eyes at the posterior border and quite at the outer 
extremity. The anterior pair (which are considerably larger) occur on the lateral 
prominence. The tentacle is absent. The palpus is very long, and gradually tapered 
from base to point. It is quite smooth. The antennse are long, slender, and finely 
attenuate at the tip. They are covered with long cilia with bulbous extremities, and 
some even extend upward on the delicate tip. The dorsal cirri are long and slender, 
with scarcely a noticeable enlargement below the filiform termination. They have 
similar cilia. The tips of the long, smooth, subulate ventral cirri extend considerably 
beyond the bases of the bristles. The ventral papilla shows slight development. 
The whitish ovoid scales (PI. XVIII. fig. 7) entirely cover the back, and indeed 
considerably overlap. The larger processes are visible under a lens, so that the scales 
appear slightly pilose. The whole scale is covered with spines, which commence 
anteriorly as very minute structures, but posteriorly form long and conspicuous conical 
processes. The posterior and outer borders are furnished with long and slender cilia. 
