when closed. Second gnathopod having merus produced distally into a sharp tooth with a small tuft of setae near the apex; carpus short, triangular, cup-like, its posterior margin bearing many transverse rows of long setae; propod very large, longer than the whole of rest of limb, oblong, margins parallel, posterior margin with about 10 small tufts of long setae, similar tufts or short transverse rows sometimes present on anterior margin and inner surface; palm nearly transverse, well defined, and usually with 2 irregular teeth, the larger flat-topped; finger arising from near the centre of distal end of propod, very short and stout, not longer than palm, its end roundly truncate.

In other respects showing the characters usual in Melita

Female.—First gnathopod similar to that of male. Second gnathopod much smaller than in the male, the carpus longer than in male and fully half as long as the propod, propod oblong but with palm oblique and not very clearly defined, irregularly toothed; finger of normal shape, long and acute.

Colour.—Pale brown, with tints of green.

Locality.—Sydney Harbour, New South Wales; and Auckland Harbour, New Zealand.

Remarks.—In 1884 I (1884, p. 1037) described under the name Moera festiva an Amphipod of which I had collected a few specimens in Sydney

Fig. 1.—Melita festiva. gn¹ ♂, first gnathopod of male; gn² ♂, second gnathopod of male; gn² ♀, second gnathopod of female

Harbour. The species was distinguished especially by the very short and peculiar truncate finger of the second gnathopods of the male. The antenna and gnathopoda of both male and female were described in some detail, and I stated that in all my specimens the “terminal pleopoda”—i.e., the third uropods—had been lost, and they were therefore probably of large size, but that in their absence it was impossible to decide whether the species should be placed under Maera or Melit. In the next year Professor Haswell (1885, p. 105), in revising the Australian Amphipod, united Moera spinosa Haswell and M. ramsayi Haswell with Moera rubromaculata

Stimpson, which he described as a species with varying forms of the second gnathopods. He added, “Moera festiva Chilton also belongs to this very variable species.” In M. rubromaculata the third uropoda are large, with both rami equally developed, so that in this character the species agrees with the generic characters of Maera and differs from Melita. The dactyl of the second gnathopod of the male of Moera festiva differed so much from those of the other forms referred by Haswell to M: rubromaculata that I felt very doubtful of the correctness of referring M. festiva also to this species, but at that time I had no further specimens or other means of definitely settling the question.

Fig. 2.—Melita festiva. pl. 3, lower portion of third segment of pleon; pl. and urp, terminal portion of pleon, with uropoda.

In 1893 Della Valle (1893, p. 720) placed Moera rubromaculata Stimpson under the genus Ceradocus A. Costa, and so did Stebbing in 1899. Accordingly in “Das Tierreich Amphipoda,” Stebbing (1906, p. 430) gave the species as Ceradocus rubromaculatus (Stimpson), and followed Haswell in considering Moera ramsayi Haswell, M. spinosa Haswell, and M. festiva Chilton as synonyms More recently, however (1910^A, p. 643), he says, “The position of all three should rather be regarded as still doubtful. M. festiva shows agreement with Haswell's M. hamigera.”

Meanwhile Mr. Walker (1904, p. 276) had described from Ceylon an Amphipod which he named Elasmopus dubius, and had drawn attention to the resemblance between the second gnathopod of his species and that of M festiva, saying, “This species is certainly very near Moera festiva Chilton” As, however, the description of that species differed somewhat from his specimens, he thought it better to consider them as distinct, adding, “It is unfortunate that in both cases the third uropods, so important in this family, should be wanting.” The loss of these appendages in Elasmopus dubius raises some doubt as to the correctness of the genus to which the species was assigned by Walker, as in my experience the third uropods in Elasmopus are usually not much longer than the first and second, and are not so readily lost as in species of Maera and Melita.

Recently I have been going over and naming an extensive collection of Crustacea gathered by Mr. W. R. B. Oliver, and in one small tube of specimens collected under stones on Rangitoto Reef, Auckland Harbour, I found three species of Gammarids—viz., Ceradocus rubromaculatus (Stimpson), Maera viridis Haswell, and another that is without doubt the same

as M. festiva Chilton. Of this species there were only two specimens, a male and a female, but fortunately the male still bears one of the third uropods, and this has the inner branch quite short and the outer one long, thus showing the form typical of the genus Melita; in other points also the species agrees well with the characters of Melita, and must be placed in that genus. It is therefore quite different from Ceradocus rubromaculatus (Stimpson). The peculiar structure of the second gnathopod is quite consistent with Melita, for in that genus the second gnathopod in the male is usually large, and differs greatly from that of the female, assuming in several species, very peculiar and even bizarre forms, as, for example, in Melita fresneli Aud.

My Auckland specimens of M. festiva differ slightly from the Sydney specimens which have the appendages, and especially the second gnathopod, more setose; the resemblance in other respects, however, is so great that I have no hesitation in considering them as the same species. In another Amphipod, Elasmopus subcarinatus (Haswell), I have noted that some of the Australian specimens are more setose than the New Zealand ones.

Maera hamigera Haswell, with which, as Stebbing has pointed out, M. festiva shows some agreement, has the rami of the third uropods long and equal, and is a true Maera, and therefore quite distinct. Moreover, although the second gnathopods show considerable resemblance to those of M. festiva, they differ in being unequal, and in the larger one the finger, though short, has not the peculiar truncate end that it has in M. festiva. Moera hamigera has been recorded by Walker (1909, p. 335) from Suez and from Khor Dongola; and both he and Stebbing, who examined specimens from the “Thetis” Expedition (1910A, p. 600), have added to and amended the original description given by Haswell.

In the absence of any knowledge of its third uropods it is impossible to come to any conclusion as to the position of Elasmopus dubius Walker. The second gnathopods appear to show as much resemblance to the larger one of M. hamigera as to those of M. festiva, but in the absence of any note to the contrary it is to be presumed that those of the right and left sides are equal.

Maera viridis Haswell. Figs. 3 and 4.

Moera viridis Haswell, 1879, p. 333, pl 21, Fig 1. Moera inertia Chilton, 1883, p. 83, pl. 3, Fig. 3. Elasmopus viridis Stebbing, 1906, p. 445, and 1910A, p. 643; Chevreux, 1908, p. 482; Chilton, 1912, p. 131.

The species Maera viridis was described in 1879 by Professor W. A. Haswell from specimens collected at Clark Island, Port Jackson. He added to his description by pointing out the differences between this species and M. truncatipes (Spinola), M. quadrimanus Dana, and M. ramsayi Haswell.

In 1883 I described from specimens obtained at Lyttelton Harbour a species Maera incerta, pointing out that it closely resembled M. viridis Haswell and the other species mentioned by Haswell, but differed from all in the form of the second pair of gnathopods, in this respect closely resembling M. blanchardi Spence Bate.

Both the species M. viridis and M. incerta were included with others under M. truncatipes by Della Valle in 1893.

In 1899 Mr. Stebbing transferred M. viridis to the genus Elasmopus, and this view was also taken in his “Das Tierreich Amphipoda,” published in 1906, where M. incerta is ranked as a synonym of Elasmopus viridis.

In 1908 Chevreux recorded the species under the name Elasmopus viridis from several localities in the Gambier and Tuamotu Archipelagoes, and in 1912 I accepted Mr. Stebbing's identification of M. incerta with M. viridis and retained the species under the genus Elasmopus, pointing out that in it the second gnathopod was almost the same in the female as in the male.

I have recently been examining the New Zealand species of Elasmopus, and have come to the conclusion that M. viridis Haswell is too closely related to M. inaequipes (A. Costa) to be placed in a different genus, and that it is best left under Maera.

M. inaequipes, the name now used for M. truncatipes (Spinola), is recorded in “Das Tierreich Amphipoda” from the Mediterranean and from the North Atlantic (Azores); but in 1904 Mr. Walker had already recorded it under the name M. scissimana (Costa) from the west of Ceylon, and in subsequent papers he recorded it from the Maldive Archipelago and other localities in the Indian Ocean. It also occurs in Australia and New Zealand (see below). In describing the Ceylon specimens Mr. Walker says that the species (M. inaequipes) “forms a connecting-link between the genera Maera and Elasmopus. The fore part, including the third peraeopods, is typical Maera, while the massive and very spinous fourth and fifth peraeopods (a character that is much more marked in Ceylon than in Mediterranean specimens), and the comparatively short rami of the third uropods, resemble Elasmopus. Another peculiarity of the species is that the size and shape of the hand of the second gnathopods is much the same in males and females.” In describing the Maldive specimens he mentions that in them the third to fifth peraeopods are less robust and more like the Mediterranean than the Ceylon forms.

It will be seen from what has been already said that the close relationship of M. viridis to M. inaequipes has been pointed out more than once. In describing M. incerta I stated that it seemed to come nearest to M. blanchardi Spence Bate; but M. incerta is now considered the same as M. viridis Haswell, and M. blanchardi is ranked in “Das Tierreich Amphipoda” as a synonym of M. inaequipes, being presumably the female.

The resemblance between the two species M. inaequipes (Costa) and M. viridis Haswell is emphasized by one or two special points. Thus in 1904 Walker pointed out that in M. scissimana (Costa)—i.e., M. inaequipes —the second gnathopods in the female are of much the same size and shape as in the male. In my MS. notes I had previously recorded the same peculiarity in M. viridis, though this was not published till 1912. In the genus Elasmopus, to which M. viridis is assigned by Stebbing, there is usually a marked difference between the sexes in the second gnathopods, and there is considerable difference in some of the other species of Maera. Both species, again, have a slight depression or emargination towards the distal end of the anterior border of the carpus in the first gnathopod.

There is similarity also as regards colour. Thus in “Das Tierreich Amphipoda” Stebbing gives the colour of M. inaequipes as “dorsally green bronzed with a little red, gnathopods 1 and 2 tinged with green, other appendages pellucid pinkish.” Haswell gives the colour of M. viridis as “light green”; the New Zealand specimens are also a light green, occasionally tinged with pink on the appendages.

From the discussion given above it will be evident that M. inaequipes and M. viridis present many points of resemblance, and that they cannot be placed in different genera. I prefer to keep them both in Maera, though

Fig. 3.—Maera viridis. Second gnathopod of male, from a Lord Howe Island specimen.

in the short third uropoda and in the widened joints of the last pair of peraeopoda M. viridis certainly approaches to Elasmopus, and naturally in the present state of our knowledge the distinctions between the genera are somewhat artificial.

In the New Zealand specimens of M. viridis that I have examined the palm of the second gnathopod is transverse or a little projecting, and it is usually straight or even, though sometimes showing slight indications

Fig. 4.—Maera viridis. Second gnathopod of male, from a Port Jackson specimen.

of a central notch and of a narrower depression next to the defining tooth. In a specimen from Lord Howe Island that I think must belong to the same species the defining tooth (Fig 3) is much longer and better marked and the palm more uneven, the median notch, however, being shallow and