48 ORCHESTTID^. 



parallel with the superior ; the wrist is short and in- 

 feriorly produced. The second pair of legs are formed 

 upon the same type, and are scarcely larger than the first. 

 The walking legs are all short and stout, terminating in a 

 sharp curved finger ; the caudal appendages are very short 

 and strong, and fringed with but few spines ; the terminal 

 appendage is deeply cleft. 



The animal is not much compressed, and all the seg- 

 ments of the body are uniform in length : a circumstance 

 which enables it to roll itself into a more perfect sphere 

 than Amphipods generally do — a fact by which it may 

 readily be detected amongst a number of other species. 



We have never seen any of this individual species 

 alive ; but in dead specimens the eyes lose all colouring 

 matter. The antennae are short and slight, gradually de- 

 creasing in diameter from the base, the first joint being 

 the largest, the rest gradually smaller, and the articuli of 

 the flagella lessen in the same degree, so that there is no 

 decided distinction between their respective peduncles 

 and flagella. 



The walking legs are all strong and short, the ante- 

 penultimate being shorter than the two posterior. They 

 are all furnished at the extremity of the foot with two 

 stout spines, curved at the apex, and serrated on the 

 sides facing the finger against which they impinge when 

 closed (A). 



The animal generally is free from hairs or spines, some 

 small ones, however, exist upon the 

 antennae, and a few others may be 

 found upon the legs, short and some- 

 what pyriform in shape, with the apex 

 cleft into two equal parts {k'^). 



The integument under the micro- 

 scope shows the T-like mark peculiar 



