Crustacea.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 631 



(he gives the length as 5 mm.), for in such specimens the various peraeopods are of 

 more uniform length, v^hile in fulty developed specimens the last two pairs are, as 

 described by Dana, much longer than the others. In the same year Mr. Stebbing 

 described a new species, Melita zeylanica, also from Ceylon, which he could not 

 reconcile with Dana's description and figures. From a comparison of his description 

 with that given by Walker and with the New Zealand specimens, there can, I think, 

 be no doubt, however, that Stebbing's species is the same as Dana's, the colour and 

 gnathopods especially being practically identical. 



Some of the confusion has no doubt arisen from the fact that the first and second 

 gnathopods of the male vary considerably, according to the state of their develop- 

 ment : thus, in immature specimens the first gnathopod has the finger attached 

 to the propod in the normal way, and the gnathopod does not then differ very much 

 from the corresponding appendage in the female ; in fully matured specimens, how- 

 ever, the end of the propod is somewhat excavate, the finger is attached about the 

 middle of the distal extremity, it is much curved, and the postero- distal angle of the 

 propod is produced into a rounded setose lobe against which the finger impinges. In 

 the same way the peculiar characters of the second gnathopod, with the finger curved 

 in on its inner concave surface, are attained only in fully adult males ; in younger 

 forms this gnathopod is much more like that of the female, though it may have the 

 propod much larger in proportion to the size of the body. There can be no doubt 

 that Stebbing is right in saying that the figure which Dana labels as the female is 

 shown from the form of its second gnathopod to be a male ; the other figure, labelled 

 " Male," has the second gnathopod larger than it usually is in the- female, and was 

 probably taken from a somewhat immature male, though Dana considered it to be 

 the female, and accidentally transposed the sex signs in his plate. The teeth on the 

 terminal segment of the pleon appear to be somewhat variable : in young specimens 

 these segments are quite smooth ; in others they have teeth on the fourth and fifth 

 segments, as described by Walker ; while in others again I have been able to find 

 them only on the fifth.* 



This species appears to bear in colour and in other respects a very close 

 resemblance to M. palmata (Mont.), about which there seems to have been the same 

 confusion as regards the shape of the first gnathopod, but it differs from that species 

 in the shape of the second gnathopod in the male. M. inaequistylis is now known 

 to occur in New Zealand, the Auckland Islands, and in Ceylon, and therefore must 

 have a very wide range in southern seas. 



Dana had originally described two species, Amphitoe (Melita) inaequistylis and 

 A. {Melita) tenuicornis, though afterwards uniting them as the two sexes of one 

 species under the name Melita tenuicornis, and this name has been used for the 

 species until a few years ago. Stebbing has, however, revived the name M. inaequi- 

 stylis, according to the rule of page precedence, and I have also used this name in 

 order to avoid further confusion ; but, seeing that Dana himself and all subsequent 

 writers had referred to the species as M. tenuicornis, I think it is a pity that the 

 name M. inaequistylis was not allowed to remain in the oblivion in which it had 

 long been resting. 



* Canon A. M. Norman has called attention to a similar variability in the sculpturing of the pos- 

 terior margins of the pleon in M. ohtusata (Montagu) : Ann. and Mag. Nat. Hist., ser. 6, iv, 1889, p. 132. 



