206 
THE VOYAGE OF H.M.S. CHALLENGER. 
preparation renders its presence doubtful. The pharyngeal region presents the usual 
anterior tooth. The prov^entriculus shows only the transverse striation of the com- 
pressed muscles in the preparation, but glandular papillse are probably present 
internally. 
Each foot has dorsally a short and somewhat cylindrical cirrus, which, in the 
compressed specimen, does not project so far outward as the setigerous region. The 
latter anteriorly bears a tuft of jointed bristles, the shafts of which are for the most- 
part curved below the dilated tip. The distal appendage is minute, with a terminal 
hook and a basal projection, so that it appears bifid (PI. XXXIVa. fig. 11). Two other 
singular bristles occur in the same group : one is a long and slightly curved form with 
an oblique tip like a beak (probably a modification of the shaft of the jointed 
kind) ; the other has a shaft of similar length, w^hicli distally is flattened out so as 
to form a spathulate tip with a terminal filament, as in certain Sabellidm and in 
Magelona. In addition to these, at and behind the twelfth foot, a tuft of long and very 
fine hair-like bristles is present. These are often broken, as in the figure. 
Seven segments (viz., from the sixteenth to the twenty-second bristled segments) of 
the body posteriorly are filled with the reproductive products, and are densely granular 
and opaque, while two early embryos are in proximity externally (PI. XXXIII. fig. 16). 
The latter are somewhat conical, one end being blunt, wfith two lateral bosses and 
three median cirri ; the other, apparently the posterior, being pointed and furnished 
with at least one cirrus above the termination (the other perhaps having fallen oif). 
The central region of the embryo is occupied by the same deep yellowish granules as in 
the body of the adult, while externally there are traces of several feet. 
The embryos of this genus somewhat resemble those of Syllides gmUigera, Krohn. 
The minute size of this form renders its diagnosis somewhat difficult, but it leans rather 
to Exogone than to any of the allied genera. 
SphcerosyUis, Claparede. 
Sphcerosyllis kerguelensis, n. sp. (PI. XXIX. fig. 5 ; PI. XXXIII. fig. 10 ; PI. XV a. 
fig. 22). 
Habitat. — 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. 
A minute example, barely 5 mm. in length and less than 1 mm. in breadth. 
The body has a fusiform shape, rather more tapered posteriorly than anteriorly, and 
comprising twenty-six setigerous segments. 
