Gnathopod 2 similar to the first in both sexes, but slightly smaller and with basal joint straight. Basal joint of peraeopoda 3–5 moderately expanded, oval, posterior margin with minute shallow crenations or serrations. Uropods 1 and 2 slender, similar, the outer ramus much shorter than the inner, inner margin of each ramus fringed with very minute spinules. Uropod 3 stouter and shorter, branches broadly lanceolate, about as long as peduncle. Telson oval, narrowing posteriorly, margin entire or with one or two minute setules on each side of the apex.

Length, about 9 mm.

Locality.—Lyttelton Harbour.

This species shows considerable resemblance both to A. cirrus (Bate) and to A. jurinei (M.-Edw.). If differs from the first in having no dorsal teeth, in this respect agreeing with A. jurinei, but the shape of the third pleon segment agrees closely with that of A. cirrus, thus differing from A. jurinei. The telson agrees closely with that of A. jurinei. In neither of these species does Stebbing speak of any sexual differences in the gnathopoda. Walker (1912, p. 600) has drawn attention to the variation in the shape of the third pleon segment in A. jurinei, and to sexual differences in the antennae in that species. Unfortunately the antennae are wanting in my specimens of A. translucens, and I am therefore unable to say whether similar differences are to be found in it.

Apherusa levis (G. M. Thomson). (Fig. 2, A to F.)

Amphithonotus levis G. M. Thomson, 1879, p. 330, pl. 16, figs. 1–4; 1881, p. 215, pl. vii, fig. 6: Thomson and Chilton, 1886, p. 148: Stebbing, 1906, p. 741.

This species was described by G. M. Thomson in 1879, and was referred to the genus Amphithonotus as agreeing well with the generic characters given by Spence Bate in the Catalogue of the Amphipoda of the British Museum. It appears, however, that the species at that time referred to Amphithonotus really belong to other genera, and the genus therefore lapsed. I have had some difficulty in deciding which is the proper genus to which Mr. Thomson's species should be referred, but its resemblance in nearly all points to the preceding species, Apherusa translucens, is so close that I am putting it down to the same genus. The only point in which it differs from Stebbing's description of the genus (1906, p. 304) is that the telson is distinctly cleft posteriorly, though not deeply so, while he describes the telson as being “entire.” I presume, however, this means “simple”—that is, not divided—and the telson of the present species could quite well come under this description. Moreover, some of the species which he ascribes to Apherusa have the telson distinctly toothed or serrate posteriorly, and the margin therefore not entire.

Apherusa levis agrees with A. translucens in having the first and second gnathopods in each sex similar, the first being very slightly larger than the second, and both pairs in the male being considerably larger than corresponding pairs in the female. It differs, however, in the presence of a well-marked rostrum and in the shape of the telson; there are also slight differences in the gnathopods. It may be re-defined as follows:—

Body quite smooth, without dorsal teeth. Cephalon produced into a distinct rostrum. Eye large, oval with anterior margin straight or slightly