The mouth parts are shown in position in fig. 4. In front is the labrum (a), the end of which is densely beset with fine setæ projecting radially from the tip as centre. When dissected out the labrum appears to consist of two plates each more or less triangular (fig. 6).

The mandible is strong, it bears a three-jointed appendage, second joint the longest, third fringed on one side with setæ projecting perpendicularly to the joint and increasing regularly in size towards the distal end of the joint. There is a large molar tubercle, the end of which seems to bear rows of short setæ.

The cutting end of the mandible consists of two sharp teeth, one longer than the other; below this there is a movable portion also ending in sharp teeth, and below this again a double row of strong setæ. (See fig. 5.)

The first maxilla (fig. 7) consists of two plates, the outer longer than the inner, bearing at the end strong setæ, some of which are branched, the outer edge and inner portion thickly covered with long very fine setæ; the inner lobe bears on the rounded end several long setæ, somewhat separated from each other, each plumose more especially towards the end; the distal and inner portions thickly covered with fine setæ similar to those on the outer lobe.

The second maxilla (fig. 8) consists of a stout basal portion bearing three overlapping plates: on the outer plates are long setæ, each bearing short pieces projecting at right angles to the seta. (See fig. 8a.)

On the third and inner plate are long plumose setæ, and on the inner edge of the base is a row of long plumose setæ similar to those on the inner lobe. The whole of the inner lobe, the inner portions of the two outer lobes, and some parts of the base, are covered with fine setæ similar to those on the first maxilla.

The maxillipede (fig. 9) bears at the base an irregularly rounded plate (fig. 4 f) which probably is homologous with a similar plate found in Idotea and Limnoria; the basal joint is long, its inner edge towards the distal end is fringed with long plumose setæ, and there is a lobe apparently connected with the first joint; this lobe bears plumose setæ on the inner edge, and simple setæ on the outer side and distal end. The other joints of the maxillipede present nothing remarkable, and their form can be best understood from the figure.

The coxæ of all the legs can be readily seen to be simply the basal joints of the legs. In the first four pairs of legs the coxa projects slightly forwards, and is tipped with a few short setæ; in the last three pairs it projects backwards similarly. (See fig. 11.)

In the first pair of legs the distal end of the meros is produced anteriorly and is fringed with setæ, the carpus is longer than broad and

has a tuft of setæ on the inner edge, the propodos is not very large; in the centre of the palm are a few short hairs set on the tip of small teeth-like projections. The other legs present nothing remarkable; the last three are abundantly covered with long stout setæ (see fig. 11); in all the dactylos is slender and the end forms a distinct claw having setæ arising at its base (fig. 11a).

In the pleon a somewhat remarkable feature is presented by the segments (except the first) having the integument produced downwards as in the first three segments of the pleon in Amphipoda, thus forming lateral shields protecting the pleopoda. The first pair of pleopoda differs from the others; it consists of a small basal joint bearing two oblong plates, the large one having a few setæ at the end (fig 12). It appears to form an imperfect operculum for the other pleopoda. In the others there is a basal joint as before; from this spring two lobes, the smaller oval with margin entire, the larger sub-oblong, inner edge fringed with simple setæ and bearing at the end another small joint fringed with plumose setæ (fig. 13).

The sixth segment of pleon is united to the telson, its inferior edge bears four strong slightly curved setæ. The sixth pleopod is more like one of the last three pairs of pleopoda in Amphipoda than anything I know of among the Isopoda; the upper surface of the peduncle is broad and slightly concave, the outer upper edge fringed with setæ, while the inner upper edge is straight. At the end of the peduncle there is one strong seta below and two or three above, the rami are sharply pointed and bear both stout setæ and longer fine hairs (fig. 14).

Throughout the whole of the body and the appendages the integument is covered with very short setæ arranged more or less regularly in interrupted rows. These setæ are very small and can scarcely be seen without a ¼-in. objective (fig. 15). Besides this along the dorsal surface are scattered a few long fine hairs.

The alimentary canal is generally full of black matter of some kind,— food, I suppose,—and hence can be readily seen through the transparent integument. It is shown in fig. 1.

The animal I have thus described is interesting and important, because it combines characters belonging to different groups. In the elongated form of the body, in the antennæ and in the plate at the base of the maxillipede, it resembles Idotea, it differs very much from this genus, however, in the form of the abdomen and in the fact that the mandible has an appendage. In this latter respect and in the cylindrical elongate body it resembles Anthura and Paranthura, and it thus to a certain extent serves to connect the Anthuridœ with the Idoteidœ. In the long abdomen composed of separate segments it differs both from the Anthuridœ and the