4 Transactions. 



It is therefore evident that Panoploea debilis (G. M. Thomson) is indeed 

 the same as Pherusa novae-zealandiae G. M. Thomson, but was thought 

 to be different owing to the errors in the original description and figures ; 

 and that the differences pointed out by , Walker between his Orudarea 

 longimana and the description of Pherusa novae-z^alandiae are due to the 

 fact that the original description was based on the examination and 

 confusion of two different species. 



The history of this species has perhaps been detailed at tedious length, 

 but it is interesting as another example of the necessity of examining 

 type specimens, whenever they are available, in order to settle disputed 

 points, instead of trusting too greatly to published descriptions and figures 

 and relying too much upon their accuracy. 



The exact generic position of this species is a little doubtful, owing to 

 the fact that in the group to which it belongs there are so many genera 

 much alike and distinguished by characters which are perhaps not all of 

 generic importance. It will be seen that the species was first placed 

 under Pherusa, then under Panoploea, next under Acanthozone, then under 

 Oradarea (a genus specially created for it), and finally under Leptamphopus. 

 In Das Tierreich Amphipoda there is only one other species, L. longimana 

 (Boeck), placed in this genus, and that was originally described by Boeck 

 under the genus Amphithopsis. 



If we compare the species under consideration with the generic 

 characters of Leptamphopus as given by Stebbing (1906, p. 293) it is 

 found to agree in most points. The first point mentioned, however, 

 " Body not acutely dentate," requires some modification, for in this 

 species the last segment of the peraeon and the first two of the pleon 

 are dentate ; again, in the generic characters it is stated that there is 

 no accessory flagellum, though Walker describes and figures one in the 

 specimens of this species obtained from Cape Adare, and his observation 

 is confirmed by Chevreux, and there is certainly a minute accessory 

 flagellum in a specimen in my collection collected at the Softth Orkneys 

 by the " Scotia " Expedition. On the other hand, there is none in the 

 New Zealand specimens nor in the northern species L. longimanus (Boeck). 

 In the mouth parts there is nothing that appears to me specially charac- 

 teristic of the genus, which seems best recognized by the long slender 

 gnathopoda and the entire telson. Most of the characters of Leptamphoptcs 

 are the same as those of Djerboa Chevreux, but in that genus the telson 

 is deepty cleft. 



The following brief description will be sufficient to distinguish L. novae- 

 zealandiae from the northern species, L. longimanus : — 



Back rounded, peraeon segment 7 and pleon segments 1 and 2 each 

 produced postpriorly into a dorsal tooth. Antennae subequal, slender, 

 about as long as body. Antenna 1 with second joint of peduncle produced 

 on each side into a short subacute lobe, a minute accessory appendage 

 present in Antarctic specimens but not in those from New Zealand. 

 Gnathopod 1 with carpus and propod subequal, narrow-oblong, palm short, 

 oblicpie. Gnathopod 2 much longer and more slender, carpus and propod 

 elongate, linear, with small tufts of setae on their posterior margins, propod 

 longer than the carpus, palm short, oblique. IJropods 1 and 2 with outer 

 brancli much shorter than the inner; uropod 3 with basal joint acutely 

 produced on inner side, outer branch not much shorter than inner, both 

 lanceolate, slightly flattened and broader than in uropods 1 and 2, inner 

 branch with an elevation or ridge on its upper surface near the inner 

 margin. Telson tapering slightly, extremity broadly rounded or truncate, 

 sometimes a little irregular, and with one or two minute setae. 



