364 
THE VOYAGE OF H.M.S. CHALLENGER. 
beyond the branchiae ; and they resemble those of Trophonia plumosa, except perhaps 
that the transverse bars are on the whole more densely grouped in some of them 
(PI. XXIIIa. fig. 1). The first three pairs of bristle tufts, l)oth dorsally and ventrally, 
may be termed long. The fourth and fifth are only elongated to a certain degree 
ventrally. At the tenth foot the ordinary condition is well seen, viz., dorsally a short 
tuft of finely tapered bristles, which are more closely and more deeply marked by trans- 
verse striae than in the common species ; and ventrally a series of characteristic hooks 
(PL XXIIIa. fig. 2), which show a smooth, slightly tapered distal region with a curve at 
the extremity, then a shaft with about four very boldly marked transverse striae (often 
the seat of fracture), which are separated l^y intervals generally greater than the 
diameter of the shaft, and sometimes twice as much. Finally, these are followed Ijy a 
series of finer striae, very closely arranged. 
Posteriorly the dorsal bristles (PI. XXIIIa. fig. 3) remain very much the same, the 
most complete forms showing a minute hook at the tip, as in the figure. So few, how- 
ever, are uninjured that some caution is necessary in predicating from this p>reparation. 
The posterior hooks, again, show a more slender distal region with the curves better 
pronounced. There are only two or three of the boldly marked transverse l3ars. In 
certain prejDarations both of these and the anterior hooks, fine transverse striae are observed 
running upward from the base of the shaft almost to its extremity, the distal region alone 
being translucent. 
The skin is much less prominently papillose than in Trophonia plumosa, tlie 
rudimentary feet (carrying the bristles) showing only a few short clavate papillae. 
Very few parasitic Infusoria appear on the frontal Inistles of this species. 
The specimen has a vast number of dark olive ova, partly floating freely in the 
perivisceral cavity, but chiefly attached to racemose ovaries covering an extensive area, 
and in all stages of development. 
In the intestine are masses of very coarse sand-particles, a few sponge-spicules, and 
parasitic Gregarinae. 
It is difficult to state precisely what the relationship of Kinberg’s Piromis arenosus,^ 
from Port Natal, is to this species. It does not seem to be identical. 
Trophonia kerguelarum, Grube (PI. XLIV. figs. 9, 10 ; PI. XXIIIa. figs. 4-6). 
Trophonia kerguelarum, Grube, Annelidenausbeute von S.M.S. “Gazelle,” Monatsber. d. k. 
preuss. Akad. d. Wiss. Berlin, von Aug. 1877, p. 539. 
Habitat. — Numerous examples were dredged at Station 149 h (off Cumberland Bay, 
Kerguelen), January 29, 1874; lat. 48° 45' S., long. 69° 14' E.; depth, 127 fathoms; 
surface temperature, 39°‘8; sea-bottom, volcanic mud. Grube’s forms were procured in 
Successful Bay, Kerguelen. 
^ 0/versigt k. Vetensk.-Alcad. Forhandl., 1866, p. .338. 
