500 
THE VOYAGE OF H.M.S. CHALLENGER. 
posterior end the tube is more chitinous. Various external growths such as Hydrozoa 
and Polyzoa are attached to its external surface. 
Unfortunately no example sufficiently preserved for minute examination exists, and 
though, after failure to remove the animal satisfactorily from its tube, a section of both 
was made, little reliable information with regard to the adherent animal w^as obtained. 
The inner or chitinous lining of the tube is perfectly hyaline and translucent. 
The Dasychone luctuosa, Ehrenberg,^ from the Eed Sea, seems to be a nearly allied 
species. 
Dasychone japonica, n. s]3. (PI. XXXa. figs. 22-24; PI. XXXIXa. fig. 5). 
Habitat . — Dredged at Station 233a (off Kobe, Japan), May 19, 1875 ; lat. 34° 38' N., 
long. 135° 1' E.; depth, 50 fathoms; surface temperature, 62°'6 ; sea-bottom, sand. 
The specimen is of considerable size, measuring 70 mm. in length, the branchiae 
making up 18 or 20 mm. of this total. The diameter anteriorly is fully 5 mm. 
The animal is somewhat softened, but the body appears to have the ordinary 
form, viz., a round dorsal surface and a flattened ventral surface. Dorsally only the 
cephalic median groove is present. Ventrally the median furrow courses forward to the 
second segment behind the anterior region, splitting it obliquely to the right of the 
middle line, cutting off an angle from the segment in front of it, and apparently 
terminating in the right lateral furrow between it and the last thoracic segment. The 
body is pale, with the exception of a number of purplish-brown specks over both ventral 
and dorsal surfaces of the thoracic (anterior) region, and a small brownish pigment- 
speck between the setigerous processes and uncinigerous rows. 
The cephalic collar begins as a prominent lobe at each side dorsally, passes down- 
ward without a break, though gradually diminishing in depth to the ventral median lobes, 
which are rather thick and bluntly triangular, the apex being external. Both sides of 
the collar are speckled with dots of brownish-purple. 
The branchiae seem to number thirty-eight or forty in each fan, but all the radioles 
had been injured except one. They are beautifully striped with alternate circular bands 
(in mass) of purplish and reddish brown. The radioles are somewhat firm rods, . provided 
externally with ligulate processes in pairs (PI. XXXIXa. fig. 5). Some of these are 
longer than others, but no definite regularity in this respect is visible ; and in the same 
way some are coloured and others pale, as they happen to come in the line of pigment or 
otherwise. The shorter processes are often fusiform. The first of the series occurs as a 
single filament between each fork above the web. The axis of the radiole shows a largely 
developed cartilage, which is composed of a closely arranged series of transversely 
1 Gmbe (Anneliden des rothen Meeres), Monatsber. d. h. preuss. Akad. d. Wiss. Berlin, 1869, p. 37 (sep. Ahd.). 
