136 THE VOYAGE OF H.M.S. CHALLENGER. 



The maxillse appear to be unrepresented. 



The maxillipedes (fig. 3) are like those of other species ; the outer margin of the four 

 joints of the exopodite are fringed with long branched hairs, the inner margin of the same 

 joints are delicately pilose, as also the broad basal joint of the appendage and the endo- 

 podite ; the latter terminates in a subacute point ; just before the extremity are a row of 

 eight of the peculiar bodies that are found in this situation in most Lsopoda ; these are 

 shown more highly magnified in fig. 4; the denticulate margins of the swollen dorsal 

 extremities of these structures are particularly distinct and suggest that the}- serve to 

 interlock the appendage with its fellow of the opposite side. 



The first 'pair of thoracic a/ppendages 1 (fig. 5), as in other species, are modified into an 

 operculum, which extends to the extremity of the rostrum, and of course entirely covers 

 the subjacent mouth appendages ; each of these appendages, which are closely apposed in 

 the middle line, consists of five joints ; the two proximal joints are short and rounded; the 

 third joint is the most important in the whole limb, the two distal joints are short (there 

 is evidently a terminal joint missing). Both margins of this appendage are densely pil< ise : 

 the outer margin of the third joint has a row of widely-separated, long, plumose hairs 

 like those which fringe the maxillipedes ; these were continued in one instance for a short 

 distance on to the fourth joint ; the upper and inner margins of the three terminal joints 

 are fringed by two rows of entirely similar hairs. 



Of the remaining thoracic limbs one of each of the four pairs were present ; the two 

 anterior pairs of limbs differ from the posterior in being very much more slender than 

 the latter. 



One of the anterior appendages is figured in PL XVIII. fig. G. The proximal joint 

 is the longest, the two next subequal in length and each of about one half the length of 

 the proximal joint ; the next joint is a little shorter as well as more slender ; the fifth 

 joint is longer and narrower, while the terminal joint is the shortest and armed with a 

 claw at its extremity. The distal joints of the appendages are furnished along the inner 

 margin with strong spines as well as with long slender hairs. 



The third and fourth pairs of ambulatory limbs (fig. 7) are very much the same in 

 structure, but the joints of which they are composed, that is to say, the three proximal 

 joints, are much stouter and stronger than in the more anterior thoracic appendages ; the 

 distal joints are much more slender than the proximal joints, and are, in fact, very similar 

 to those of the preceding appendages ; the fourth joint is rather more swollen, and the 



1 On both of these appendages, or rather inside them, in the second and third joints along the inner margin were a 

 number of round, granular, nucleated bodies, which I believe to be the eggs of a parasitic Nematode, as there was in each 

 appendage a young worru, evidently a Nematode, curled up among the eggs. I think it worth while to record this 

 fact, as it is a remarkable situation in which to find these parasites. Dr. v. Willemoes-Suhm has spoken of a species of 

 Gordius which he found parasitic in a deep-sea shrimp curled up under the carapace (Proc. Hoy. Soc, vol. xxiv. p. 572), 

 and I have myself called attention to a parasitic (?) Nematode which frequents the body of Serolis nesera (Zool. (Jball. 

 Exp., part xxxiii. p. 60, note). The present is another instance of the occurrence of these parasites in deep-sea Crustacer . 



