Peduncle short, narrower than the capitulum, into which it insensibly blends; strongly wrinkled; surface of attachment wide; position with respect to the branches of the coralline, various.

Size and Colour.—The largest specimen, including the peduncle, was half an inch in length, and 3/10ths of an inch across the capitulum; colour, after having been long in spirits, brownish-yellow.

Filamentary Appendages, one on each side, short, tapering and pointed; seated on the posterior margin of a slight swelling beneath the basal articulation of the first cirrus; they are about equal in length to the pedicels of this cirrus.

The Mouth is directed abdominally; labrum much produced downwards, so as to be far separated from the adductor muscle; moderately bullate, forming about one third of the longitudinal axis of the entire mouth; upper part forming a slightly overhanging prominence; crest with a row of blunt, bead-like teeth, and externally to them there are numerous curved short bristles.

Palpi ([Pl. X], [fig. 8,]) unusually narrow, a little hollowed out along their inner margins; pointing towards the adductor muscle; thickly covered with doubly serrated bristles.

Mandibles, with either two or three teeth; inferior angle narrow and tooth-like; both sides covered with strong bristles or spines, projecting beyond the toothed edge.

Maxillæ, with two large upper spines, and a third rather distant from them; beneath these, there is a wide notch or hollow; inferior part square, projecting, bearing six pair of moderately long spines, (of which the central one is the longest,) mingled with finer ones.

Outer Maxillæ, with a semicircular outline; the serrated bristles in front are divided into two groups; externally there is a rounded and very considerable projection covered with long bristles. Olfactory orifices slightly prominent, approximate, seated within and just beneath the rounded projections at the base of the maxillæ.

Body.—Prosoma little developed; thorax small.

Cirri, extremely long, but slightly curled, capable of being protruded so as almost to touch the base of the peduncle or the surface of attachment; segments short, extraordinarily numerous. In the three posterior cirri (excepting the rudimentary rami), each segment supports two long, slightly serrated spines, with two or three minute intermediate ones, and with one or two very short, thick spines on the inner and upper lateral margins: dorsal tufts with only two or three long, fine, unequal spines. All the segments are extremely flat, broad, short, with their anterior faces not protuberant; the greater number of the segments, especially the lower ones, have very obscure articulations, to be seen only with a high power, and these can be capable of little or no movement.