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Transactions. 



about as long as the ischium, and, like the two preceding joints, free from 

 setae ; the propod, with which the carpus is coalesced, is very large, fully 

 as long as the rest of the limb, and has the posterior distal angle produced 

 so as to form with the very strong finger a powerful chelate appendage : 

 the anterior margin is strongly convex, the posterior is straight or slightly 

 sinuous and bears a number of setae, especially towards the distal end, 

 these setae being less numerous in older specimens ; the palm projects 

 strongly and has a blunt tooth towards the end ; the finger bears along 

 its inner margin a regular row of long setae, and near the extremity a tuft 

 containing a considerable number of setae. The shape of the propod and 

 finger will be best seen from the figure, which is taken from a fairly well 

 developed male. In one specimen examined, apparently older, the palm 

 is deeply concave, the fixed finger is longer and more joroduced, the tooth 

 on the inner margin is blunter and nearer the apex, the setae both on the 

 fixed finger and the dactyl are less conspicuous. 



Fig. 16. — Ceina egregin ; second gnathopod of iminature male. 

 Fig. 17. — Ceina egregia ; first gnathopod of female. 



In the immature males the second gnathopod (fig. 16) is of much more 

 normal shape, and in quite young forms is probably the same as in the 

 female. The figure shows one in which the carpus can still be distinguished 

 as a separate joint ; it is short and triangular, fairly well marked oft" from 

 the propod on the anterior side, and produced posteriorly into a small lobe 

 lying between the merus and propod, and appears to be more or less fused 

 with the latter ; its presence, however, is indicated even on the posterior 

 margin by a small number of setae on the posterior margin. The propod 

 is broader than in the fully developed specimens, and is subchelate, having 

 the palm transverse, slightly convex, defined by a fairly stout acute tooth 

 or spinule. The hind-margin and the palm bear numerous long setae, 



