POLYCMTA—BENHAM. 
101 
“ cirrus ” has increased in size, and has become sub-cylindrical ; the distal upper 
angle of the foot becomes produced into a distal cirriform process (? the “ lip ” of the 
chsetophore), in addition to the dorsal “ cirrus” (fig. 121). 
The neuropods decrease in size posteriorly, and the inferior angle becomes more 
marked. 
The general form of the neuropod is similar to that occurring in other Ampharetids, 
but the presence of both the proximal “ papilla ” and the distal “ supra-uncinal 
process ” seems unusual. The proximal papilla, which I have termed “ cirrus,” is 
usually regarded as equivalent to a vestigial notopod; and the distal process to the 
dorsal cirrus (cf. Fauvel (1897), Ehlers (1887) p. 220). 
The uncinus has five teeth in a single series, and a small prominence between the 
smallest of these and the rounded upcurved extremity of the plate (figs. 122, 123) ; 
it is quite similar to that figured for P. crocea by McIntosh (1885), pi. xxvi a, fig. 25). 
The structure of the gill (figs. Ill, 112). Although the condition of preservation 
is not sufficiently good to allow a thorough study of the gill to be made, the 
examination of a short series of transverse sections enables me to give an account of 
its more striking features. 
The gill axis is traversed by a canal, whose wall is composed chiefly of muscle. 
Externally there is a layer of tall columnar cells bearing a thick cuticle; within this 
is a thin circular coat of muscle, which envelopes a thicker coat of longitudinally 
arranged muscle fibres. This does not seem to be limited very definitely internally, 
for there is a layer of loose connective tissue, in which are scattered irregularly a number 
of small round nuclei. At places in the series of sections I believe that I can detect 
the remains of a thin membrane forming the lining of the axial cavity; but the tissue 
is here broken and imperfectly preserved, and it may even be that the canal is an 
artifact, and that the axis is occupied by a core of loose connective tissue. 
Running along the wall of the axis at two opposite points is a blood vessel, lying 
apparently in the longitudinal muscle coat, but in places it projects into the cavity. 
The folia or gill membranes are, of course, cut transversely; the central part 
consists of connective tissue, enveloped in the epidermis. I can see no cilia, though 
perhaps this is due to the state of preservation. A series of blood vessels is cut across, 
lying close to one another along each side, underneath the epidermis. They give to 
the section a very characteristic appearance, and seem to be connected across the 
folium; but I was unable to trace out precisely how or where they communicate with 
the axial blood vessels. 
Locality .—■ 
Commonwealth Bay, Station 3, 157 fathoms. 
Remarks-.- —That the genus Phyllocomus is rare is evident from the fact that 
although it was established by Grube as long ago as 1877 for the species 
