226 
THE VOYAGE OF H.M.S. CHALLENGER. 
Head about as long as broad ; tentacles somewhat stout, considerably shorter than the 
head. Eyes rather large, widely separated transversely, but approaching each other 
antero-posteriorly ; no trace of a lens. Palpi large, but the terminal boss is small. 
Tentacular cirri of moderate length, the longest reaching the ninth foot. Paragnathi — 
I. two points, or absent ; II. triangular groups of small points ; III. a small and some- 
what irregular series; IV. larger triangular groups than II.; V. absent; VI. a single 
point in each ; VII. and VIII. five single points, each in a lozenge. Maxillae brown, five 
large teeth below the bare region at the fang. The first segment is very little broader 
than the succeeding. The feet anteriorly have more elongated processes than in Nereis 
dumerilii, while posteriorly they are less elongated. The cirri are shorter than in the 
latter species. Dorsal bristles have comparatively short tips ; falcate bristles have 
somewhat elongated tips. 
A fragment, consisting of forty segments of the anterior region, measuring 28 mm. in 
length, with a diameter at its widest part of about 5 mm. including the bristles. 
The head (PI. XXXV. fig. 10) is about as long as broad. The tentacles are rather 
stout, and considerably shorter than the head. The basal portions of the palpi are large, 
the terminal boss on the other hand being small. The longest tentacular cirrus reaches 
to the ninth foot, but the body is much contracted in front (the proboscis being 
extruded). The eyes on each side are wide apart, and of considerable size, the anterior 
pair being the larger. There is no trace of a lens. 
The extruded proboscis exhibits dorsally a point (VI.) on each side of the basal 
(buccal) region in front of the palpi, and a somewhat triangular group of small paragnathi 
(II.) on each side of the base of the maxillae. Ventrally there is a similar but larger 
group (IV.) corresponding to the latter, and in the centre a small series (IIP), in 
a line drawn between the posterior borders of the lateral groups. The buccal (basal 
in extrusion) region has a single point of considerable size in each lozenge (formed 
by the wrinkles), in all five in number (VII. and VIII.). It is interesting that, though 
differing in number and in the outline of the spaces, these occur on the same sites as in 
Nereis pelagica, Linn. The maxillae show five large teeth, a portion at the tip being bare. 
In the variety from Cape Maclear the basal ring of the proboscis in extrusion shows 
dorsally a single point (VI.) in front of each palpus, a feebly developed double row (II.) 
near the base of the maxillae, and two points (I.) between them. Ventrally there is a 
larger patch of paragnathi (IV.) at the bases of the maxillae on each side, besides a some- 
what scattered group (HI.) in the centre. The basal collar (VII. and VIII.) has six 
points, five of them being very distinct. 
The feet as a whole do not show any marked change of series. They have the 
glandular pigment-spots analogous to those of Nereis dumerilii. The tenth foot 
(PI. XXXV. fig. 11) presents more elongated processes than in the latter species. 
Dorsally is a somewhat large tapering cirrus, which extends beyond the tip of the first 
