_Filamentary Appendages._--These, in a medium-sized specimen, are arranged on the prosoma in four longitudinal approximate rows, there being twelve in each row; those in the two outer rows are only half the length of those in the two inner rows; those nearest the thorax are the longest; there are some papillæ outside the outer rows. In a very large specimen with its capitulum 1.3 in length, these filaments were very much more numerous, and some were placed on the first segment of the thorax, and at the bases of several of the posterior cirri. Some of the filaments are bifid, trifid, and even branched. In all the specimens, at the bases of the first pair of cirri, there are, on each side, a pair of filaments, (one below the other,) pointing upwards, less than half as long as those on the prosoma: also on each side of the mouth, there is a longer and thicker filament, pointing upwards, with a few very minute scattered spines on it; the apices of these three pair of filaments, as well as of some of the others, are roughened with very minute pectinated scales. All these filaments were gorged with the branching testes. _Mouth._--The parts are closely similar to those in _P. cornucopia_; in the mandibles, the interspace between the third tooth and the inferior angle, is slightly pectinated: in the maxillæ, there are six or eight pairs of spines between the two upper tufts of fine spines. _Cirri._--These are in most respects similar, to those of _P. cornucopia_. In a specimen in which the sixth cirrus had eighteen segments, the shorter ramus of the first pair had ten segments, of which the five lower segments were thick and clothed with doubly serrated spines. In the second cirrus the anterior ramus had fifteen segments, of which the four basal ones were highly protuberant, and thickly clothed with spines. These spines, and some on the third cirrus, and a few on the first cirrus, have peculiar bent teeth, presently to be described under _P. polymerus_. These singularly toothed spines are absent in _P. cornucopia_. From the above numbers, we see that the first and second pairs of cirri have more segments in proportion to the sixth pair, than in _P. cornucopia_; and in the second pair, a fewer proportional number of the basal segments are protuberant and thickly clothed with spines. _Caudal Appendages_, shorter than the lower segments of the pedicels of the sixth cirrus, with only four articulations; rather constricted near the base. The _Ovigerous Fræna_ consist of very long and prominent folds, thinning out to nothing towards the bases of the scuta, but not furnished, as far as I could see, with glands, and therefore not normally functional.