161 



the palm, there is a row of about 7 or 8 fine seta? along the inner 

 margin and a small tuft towards the end of the outer margin : 

 the extremity is indistinctly separated from the rest of the dactylos 

 and beai's the terminal unguis and on the inner mai'gin a small 

 secondary tooth. 



The description just given and the figures 5 and 5a of Plate 

 xxiv. apply to the first thoracic leg of a fully grown male. In the 

 female and probably also in young male the limb is of the same 

 general shape, but the subchelate hand is less strongly developed, 

 the propodos being much less swollen. 



The second thoracic leg (second gnathopod) (See Plate xxv., fig. 

 1.) has the hasos and ischios similar to those of the first leg but 

 the fringe of setiB on the anterior margin of the basos is much 

 longer and contains about fifteen set;v, and the tuft on the anterior 

 margin of the ischios contains much stouter setiv : tlie meros is 

 subtriangular, narrow at the base but does not ovei'lap the carpus, 

 the posterior edge bears al)out C or 7 stout set;e and a number of 

 others more slender, and there are similar tufts at the middle of 

 the anterior margin and at the antero-distal angle. The carpus 

 is not so short and triangular as in the first leg, the anterior 

 margin is rather convex and bears a tuft of fine seta? at the antero- 

 distal angle, the posterior margin is straight and bears six stout 

 setfe increasing in length distally. The propodos is subrectangular 

 rather more than twice as long as broad, and is somewhat longer 

 than the carpus ; the anterior margin is slightly curved and bears 

 a few seta- chiefly at the base of the dactylos, the posterior margin 

 is straight and bears 5 or 6 stout sjDiniform sette and a few slender 

 ones. The dactylos is more than lialf as long as the propodos and 

 is similar to that of the first pair of legs except that it is smaller 

 and bears fewer setjy upon it. Fig. 1 of Plate xxv. represents 

 the tliird thoracic leg, but will do equally well for the second. 



The third thoracic leg (first ^^eo'eiopod) (Plate xxv., fig. 1) is 

 similar in all respects to tlie second, and is of about the same 

 size. 



The foiirth thoracic leg (second pereiopod ) (Plate xxv., fig. 2) 

 of the male is rather shorter than the two preceding legs and 

 differs from them in a few small details. The basos and ischios 

 are quite similar to those of the second and third legs, and are 

 nearly as large ; the meros and cai-pus are similar but ai-e shorter 

 and stouter in proportion ; the propodos is also stouter and has 

 the anterior margin strongly convex, the posterior margin is very 

 short and bears two very stout spiniform set;e placed side by side 

 and defining a slightly concave palm ; the dactylos is strongly 

 curved and bends back upon these two setfe so as to form a 

 powerful claw. It is only in the male that the fourth leg is thus 

 modified, in the female it does not differ appreciably from the two 

 preceding legs. 



