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Transactions. 



and the full expansion of the carpus of the fifth peraeopod are not developed 

 until after the characters of the second gnathopod have been attained. 

 In the Ross specimen the second antenna is much longer than in form 1. 

 or than it is in the Chatham Island specimens of form 2, being longer than 

 the second gnathopod, while in the Chatham Island specimen it is distinctly 

 shorter. It was this difference in the length of the second antenna, com- 

 bined with the differences in the first and second gnathopods and in the 

 fifth peraeopod, which made me first think that the Ross specimen 

 must be a different species, but comparison with the Chatham Island speci- 

 men as above described forced me to the opposite opinion. From the 



Fig. 18. — Fifth peraeopod of adult male. 



Kaiapoi Beach, near the mouth of the Waimakariri, I have several speci- 

 mens similar to the Ross one, but all more immature and having the special 

 characters of the second gnathopod less marked. I have also one specimen 

 from Waiwera, Auckland, which appears to belong to this form, though the 

 palm of the second gnathopod is not precisely the same as that figured ; 

 the rounded spinose process near the base of the finger is present as 

 in form 2, but the palm is without the defining tooth, in this respect 

 resembling form 1 ; pellucid lobes are present on the carpus and propod 

 of the first gnathopod, and the carpus of the fifth peraeopod is more 

 expanded than in the Ross Beach specimen, while the second antennae 

 are short. This Waiwera specimen thus shows intermediate characters, 

 and affords an additional reason for retaining forms 1 and 2 in the same 

 species. 



References. 



Barnard, K. H., 1916. Contributions to the Crustacean Fauna of South 

 Africa, 5, Amphipoda, Ann. South Africa Mus., vol. 15, pp. 105-302, 

 pis. 26-28. 



Bate, C. Spence, 1862. Catalogue of the Specimens of Amphipodus 

 Crustacea in the Brit. Mus., London. 



