rows of setae on both margins, palm oblique, defined by a small tooth, irregularly denticulate, the teeth varying in number and being acute or rounded at end; right and left second gnathopods often slightly unequal in size, those of the male apparently larger and with more distinctly toothed palm than in the female. Third uropods much longer than the first and second, rami equal, broadly lanceolate. Telson cleft to base, lobes bluntly conical, produced into an acute tooth on each side the terminal notch, which bears 2 or 3 spinules.

Colour.—Usually light yellowish - brown; “dirty green” (G. M. Thomson).

Localities.—Moeraki (Dunedin Museum collection); Stewart Island (H. B. Kirk); Paterson Inlet, Stewart Island (G. M. Thomson—recorded as Maera quadrimana Dana); Chatham Islands (H. B. Kirk); off Cape Maria van Diemen, dredged in 50 fathoms (C Chilton).

Distribution.—Australia, Kermadec Islands, New Zealand, Chatham Islands.

The species was originally described from Port Jackson by Haswell, and afterwards recorded under the name Megamoera thomsoni by Miers from various localities in the north of Australia. These two species were united by Haswell (1885, p. 105). I have a specimen from St. Vincent Gulf, South Australia, sent to me by Mr. S. W. Fulton, and in 1911 I recorded it from Kermadec Islands, the specimens having been collected by Mr. W. R. B. Oliver.

In 1912 I examined a few specimens from Cape Colony collected by the “Scotia” Expedition, and with some hesitation referred them to Maera mastersii, mentioning the points in which they differed from the description given by Stebbing in “Das Tierreich Amphipoda.” Mr. Barnard has since kindly sent me further specimens of the same species from Cape Town, and has pointed out that they differ in some specific characters from M. mastersii. I find that this is so, and that they belong to Maera bruzelii Stebbing, a species which I had overlooked, as it was accidentally omitted from “Das Tierreich Amphipoda.” Mr. Barnard considers the Cape Town specimens slightly different from the description of Maera bruzelii, and looks upon them as a separate variety or a closely allied species, and places them in the genus Elasmopus, to which, as I pointed out in 1912, they show considerable resemblance.

Stebbing (1910B, p. 457) gives four points of difference between M. bruzelii and M. mastersii. Two of these hold for my specimens—viz., the accessory appendage is only 4-jointed in M. mastersii but about 8-jointed in M. bruzelii, and the third uropoda reach considerably beyond the others in M. mastersii but only a little beyond them in M. bruzelii. The other two distinctions do not hold, thus the first side plate is produced forward in M. mastersii about as much as in M. bruzelii, and the palm of the first gnathopod is not quadridentate but smooth. The teeth on the palm of the second gnathopod are sometimes 4 in number.

Maera mastersii was first recorded from New Zealand by Mr. G. M. Thomson, under the name M. quadrimana Dana, in 1882. Mr. Thomson obtained several specimens with the dredge in Paterson Inlet, Stewart Island, and another from between tide-marks in the same locality. He pointed out that the specimens differed in certain respects from Dana's species, and that they differed among themselves in the structure of the second gnathopods. I find that Mr. Thomson's specimens belong to two