AMPHIPODA. CHILTON. 



57 



of the male that I had previously given of New Zealand 

 specimens in having flic meral joints of the posterior 

 peraeopoda as greatly expanded as in 8. antarctica and in 

 having the palm of the first gnathopod very distinctly 



Fig. 6 ah. StiUa t\ji>ica, Ohiltou, male. 



a. First gnathopod. b. End of palm 

 with tip of finger (more highly magnified) . 



oblique instead of being transverse, though the armature 

 of the palm itself is closely similar ( Fig. 6 a and b) . I find, 

 however, that the small specimens collected by the 

 'Endeavour," measuring only about 2 mm. in length of 

 body, have the palm transverse as in the New Zealand speci- 

 mens, which are of about the same size, and, as in them, the 

 meral joint of the posterior peraeopoda is only slightly 

 broadened. Transitional forms are also found, and it 

 appears evident that the expansion of the meral joints of 

 the peraeopods is greatest in fully developed males and is 

 gradually attained, and that in young males the palm of 

 the first gnathopod is transverse or even projecting, while 

 in the larger or older males it becomes gradually more and 

 more oblique. The expansion of the merus of the fifth 

 peraeopoda increases in proportion to the greater oblique- 

 ness of the palm of the first gnathopod. Probably in quite 

 young males the first gnathopod is similar to that of the 



