upper part
highly bullate, nearly equalling the longitudinal diameter of the rest
of the mouth, and very slightly overhanging the lower part; crest with
very minute bead-like teeth.

_Palpi_, with their inner margins considerably excised, most thickly
clothed with spines.

_Mandibles_, with three strong teeth, two unequal-sized small teeth
being placed between the first and second, thus making five altogether;
inferior angle broad, pectinated.

_Maxillae_, with its edge broad, straight, bearing about twenty pairs of
spines, shorter than the large upper spines.

_Outer Maxillae_, with the bristles in front, continuous, and without any
notch; exterior surface with a prominence clothed with long spines.
Olfactory orifices slightly prominent.

_Cirri._--First cirrus placed near to the second; posterior cirri not
much elongated, with their segments slightly protuberant, bearing four
pairs of spines, of which the lower pair is small; spines slightly
serrated. In the lower segments, these spines are exceedingly unequal in
length, the inner spines on both rami, not being above one fourth of the
length of the outer corresponding spine in each pair. The tufts
intermediate between these pairs, are not very large: on the lateral
upper rims there are some strong, short spines: dorsal tufts with short,
thick spines. First cirrus about three fourths as long as the second
cirrus, with numerous tapering segments, three or four of the lower ones
being thick and protuberant: in the first cirrus there are eleven
segments, and in the sixth cirrus, seventeen. Second cirrus, with the
anterior ramus slightly thicker than the posterior ramus: a few of the
basal segments of both rami are protuberant, and thickly clothed with
spines. In the third cirrus, the two rami are nearly equally thick, with
some of the basal segments in both clothed, like a brush, with spines.
In these brushes on the first, second, and third cirri, most of the
spines are doubly toothed, each tooth being simply conical.

_Caudal Appendages_, small, much flattened, straight on the exterior
side, and curved on the inner side, with a row of short, rather thick
spines on the crest, and a few on the exterior margin.

The _Affinities_ of this species will be given under the head of the
following, _P. sertus_.

6. POLLICIPES SERTUS. Pl. VII, fig. 5.

_P. capitulo valvarum uno aut pluribus sub-rostro verticillis instructo:
laterum pari superiore vix inferioribus longi