POTTS—POLYCHATA: AMPHINOMID£, 361 
and NV. hispida, the description of which follows), it does not appear to project so far 
anteriorly or mask the head so completely as in N. variabilis. The folded regions of 
the caruncle are separated on each side by a smooth pigmented area, which is 
always to be seen (contrast WV. hispida). 
The head bears two pairs of large eyes, barely apparent under the sides of the 
crest of the caruncle, and a slender median tentacle of small size, less than + of the 
length of the caruncle. 
The branchiz beginning on the fifth body-segment form a series of rather large 
spreading tufts, each with a definite stalk, from which arise a number of much sub- 
divided branches. In the smaller specimens the gills are much smaller proportionately 
and appear to consist each of two main divisions. The branchial cirrus occurs at 
the inner border of the dorsal bundle of setz, and is a slender, uniformly cylindrical 
structure, very little longer than the branches of the gill-tuft. The outer or dorsal 
cirrus proper has, as is usual, a thick basal division, which is in many of the specimens 
of a conspicuous orange colour, and a filiform pale-coloured distal division. This is, 
as in other species of the genus, much the longer and approximately equal in length 
to the dorsal setee. 
The setze have a more or less marked greenish colour, and, save in one case, a flexible 
consistency and associated iridescence. One small specimen, however, possesses stiff 
setze, which are, moreover, glassy and colourless, and it remains to enquire how far 
these differences of colour and texture constitute natural variations. The dorsal 
sete are of the “boldly forked” type figured by McIntosh for N. megalops and 
NV. labiatus, but, unlike the first, never show a trace of serration. The ventral setz 
are almost identical in shape with the dorsal. As.a result of careful examination 
it was found that two out of eight specimens possessed serrated ventral sete, and so 
allow us to place this species along with WV. labiatus in the group which possesses 
‘smooth dorsal and serrated ventral bristles. In the form alluded to above as possessing 
stiff setse, occasional examples were found in the ventral bundles of the middle 
segments, with a couple of well-marked serrations underneath the hooked apex of the 
longer limb. In a large specimen the ventral sete of the anterior two segments 
were largely bi- and triserrate, while in the third segment the serrations were barely 
recognisable and not met with subsequently. 
The anus occurs on a rather conspicuous papilla on the dorsum in segments varying 
from the 22nd to the 25th. 
The species appears to have affinities with .V. labiatus, McIntosh, dredged hy the 
‘Challenger’ to the south of the Philippines and lately mentioned by Moore among the 
polycheets of the Hawaiian Islands. The species agree closely in size and number 
of segments, and also in such characters as the small size of the median tentacle, the 
prominent lips from which McIntosh’s species takes its name, and the green colour 
of the setz, as well as their serration. The peculiar relation of the caruncle and 
the head is perhaps the chief reason for the separation of this species. 
Locality. Hulule, Male Atoll, Maldives, eight specimens. ‘“ Under loose coral 
stones of boulder zone lying on the bare flat reef.” 
SECOND SERIES.—ZOOLOGY, VOL, XII. 4,9 
