EEPORT ON THE ANNELIDA. 
491 
? Sabella fusca, Grube (PI. LII. fig. 3 ; PI. XXXa. figs. 4-6). 
Sahella fusca, Grube, Annel. d. rothen Meeres, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, 
June 1869, p. 36 (sep. Abd.). 
Habitat . — Dredged ofi" Port Jackson, Sydney, April 18, 1874 ; in 2 to 10 fatlioms. 
A fragment of about eighteen segments of the anterior region of a large Sabella, 
measuring 32 mm. in length (the branchiae forming 18 mm. of this) and 8 mm. in 
diameter. 
The body shows a slight median furrow dorsally, while ventrally the usual deep 
median groove comes forward to the second last scute behind the anterior region, curves 
outward to the right lateral region and up to the dorsum. 
The cephalic collar commences on each side of the deep dorsal groove, and extends 
without a break to the ventral surface, where it forms a triangular lappet on each side of 
the median fissure. The collar is prominent, and coloured deep brownish at the ventral 
lappets. 
The branchiae form a very bushy tuft on each side, consisting of several series (in 
contraction), especially toward the ventral edge of the radioles. Each fan has upwards 
of sixty radioles, of a mottled purplish-brown colour, the pinnae being darker than the 
mottled radioles. Although folded so closely in contraction, the fan in each case in all 
probability has only a single series of radioles in full expansion. The pinnae are arranged 
very closely along the radioles, and gradually diminish toward the tip, ending first in 
short papillae and then in mere crenations. The bare process at the tip is comparatively 
short and not much tapered. 
The tentacle is little more than a third the length of the branchiae, and is a simple 
tapering dark brown process attached to the dorsal edge of the fan. 
The anterior region consists of eight bristle-bearing segments. The elongated dorsal 
bristles (PL XXXa. fig. 4) possess a very slight bend toward the tip, which is furnished 
with a narrow wing and a moderately attenuate extremity. The inferior group, 
again, consists of slender bristles with shorter tips (PL XXXa. fig. 5), a more decided 
curvature, and proportionally broader wings. Both sets of bristles are unusually slender. 
Posteriorly the tips of the two kinds are not much elongated, but as the example 
possesses only a fragment of this region, little can be said on the subject. The bristles 
throughout are of a pale golden colour. 
The anterior hooks (PL XXXa. fig. 6) have the usual shape, the base being 
moderately elongated, and truncated posteriorly. It seems to be hollow. Tim crown 
has numerous minute teeth, about ten or eleven, appearing in profile above the great 
fang. The striae of the neck and body are fairly developed, but not very bold. The 
ventraHine shows a gentle convexity with an inflection posteriorly at the process. The 
hooks of the imperfect posterior region do not diverge to any extent. 
