Chilton. — Some Australian and New Zealand Gammaridae. 363 



In 1899 Mr. Stebbing transferred M. viridis to the genus Elasviopus, 

 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 Elasnwpvs 

 viridis from several localities in the Gambler 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 31. 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 peraeo- 

 pods, 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 relation- 

 ship 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 

 Sbs 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. 



