Chilton. — Some New Zealand Amphipoda. 225 



Photis brevicaudata Stebbing. (Fig. 3, A to E.) 



Photis brevicaudata Stebbing, 1888, p. 1068, pi. 108 ; 1906, p. 606 ; 

 1910, p. 648. 



Several specimens that certainly belong to this species were obtained 

 near the Gannet Islands, off the west coast of Auckland, in January, 1915, 

 at a depth of about 50 metres. The species were originally described from 

 specimens obtained by the " Challenger " Expedition off Melbourne, 

 Australia, at a depth of 60 metres, but only the female was then taken. 



My specimens agree well with Stebbing's description and figures of the 

 female ; in the first gnathopod the palm is slightly concave, as shown in 

 his detail figure. The male specimens differ from the female in the size 

 and shape of the second gnathopod, but particularly in the great elonga- 

 tion of the fourth peraeopod. The second gnathopod of the male has the 

 shape in general like that of the female described by Stebbing, but the 

 propod is larger, the palm much more excavate, and the angle defining it 

 much more marked. The fourth peraeopod in the older males is very 

 greatly enlarged, being much larger and broader than the fifth, as will be 

 seen by comparing figs. 3d and 3e. The basal joint is broad, narrowing 

 distally, the meral joint is greatly elongated, being longer than the carpus 

 and propod together ; the details as to the proportions of the joints can 

 be best learnt from fig. 3d. The other appendages agree well with the 

 description given by Stebbing. 



In the male specimen from which fig. 3b of the second gnathopod was 

 taken the first gnathopods were unsymmetrical. One, shown in fig. 3a, is 

 practically the same as that of the female. The one from the other side 

 (fig. 3c) has the propod similar to that of the second gnathopod, though 

 rather smaller, but the carpus is much longer than in the second gnathopod, 

 and therefore more like that of a normal first gnathopod. 



The great enlargement of the fourth propod in this species recalls the 

 somewhat similar development of the same appendage in Eurystheus 

 crassipes (Has well). 



Stebbing describes the telson as " very short, much broader than long, 

 apex rounded," and figures it without setules. In the specimen I have 

 examined the apex is less rounded, and bears setules on either side as in 

 P. macrocarpa Stebbing and other species of the genus. 



Jassa falcata Montagu. 



Cancer (Gammarus) falcatus Montagu, 1808, Trans. Linn. Soc, vol. 9, 



p. 100, pi. 5, fig. 2. Podocerus validus Thomson and Chilton, 



1886, p. 143. Jassa pulchella and Jassa falcata Stebbing, 1906. 



pp. 654, 656. J. falcata Sexton, 1911, p. 212; Chilton. 191 2, 



p. 511 ; Stebbing, 1914, p. 371. 



This species had been collected in New Zealand by Thomson about the 



year 1885, and identified with Dana's Podocerus validus from Rio de Janeiro. 



About the same time I had obtained numerous specimens from a buo)^ in 



Lyttelton Harbour, and had figured both male and female forms. The 



species has proved to be specifically identical with Jassa falcata, originally 



described by Montagu from the south coast of England, and now known 



to be very widely distributed both in northern and southern seas. There 



are probably two forms of the male, both different from the female, and the 



immature stages in the development of the adult male characters have led 



to much confusion and multiplication of species. Fuller accounts will be 



found in Mrs. Sexton's paper quoted above and in my report of the 



Amphipoda of the " Scotia " Expedition (1912, p. 351). 



8 — Trans. 



