4G 



MEMOIES OF THE QUEENSLAND MUSEUM. 



llagelliiui shorter than the peduncle, containing about 10 joints. This appendage 

 appears to be the same in the male and in the female. 



Fig. 1. — First antenna of male (Brisbane specimen). 

 Fig. 2. — Second antenna of male (Brisbane specimen). 



Antenna 2 appears to vary considerably according to age and development, 

 becoming stouter, especially at the base, in older specimens. In a fully developed 

 male (fig. 2) the first three basal joints of the peduncle are short and very broad; 

 the fourth joint is fully as long as all the preceding though much more slender, 

 and is produced at the apex on the inner side into an oval lobe which when 

 fully developed reaches nearly halfway along the fifth joint of the peduncle; the 

 fifth is only half as long as the preceding ; the flagellum is shorter than the last 

 joint of the peduncle and consists of about 5 or 6 joints. The lobe at the end 

 of the fourth joint of the peduncle varies in- size in different specimens according 

 to their development; in one specimen from Brighton, the second gnathopod of 

 which is shown in figure 10a, the antennal lobe is quite short, the basal joints of 

 the peduncle are not so broad and the fourth joint scarcely so long as in more 

 mature specimens (fig. 2a). In a specimen from Lake Roto-iti which, judging 

 by the second gnathopod, is an undeveloped male, the second antenna (fig. 2&1 



Fig. 2a. — Second antenna of male, immature (Brighton specimen). 

 Fig. 2b. — Second antenna of male, immature (Roto-iti specimen). 



is very stout, the fourth joint being almost as stout as the preceding but without 

 any trace of the apical lobe, while the fifth joint is larger in proportion than in 

 the mature males from Brighton and from Brisbane. In some of the specimens 

 the proximal joints of the flagellum appear to be partially fused though the line 

 of junction is clearly visible ; like the peduncle they bear a few fine seti^. In the 

 females the second antenna remains much more slender and without the lobe on 

 the fourth joint. 



