22 G. 0. Sårs. 



endopodite is divided into 5 setiferous lobules, the 3 inferior 

 of which are rather small and conical in form. Of the 

 2 remaining lobules the upper one is much the larger, 

 and, like the other, is densely fringed with a regular series 

 of very delicate, upward-curving setæ. The exopodite has 

 the form of an oval lamella movably articulated to the 

 stem, outside its terminal lobe. This lamella is rather 

 large, greatly constricted at the base, and fringed all round 

 with strong, ciliated setæ. The epipodite, which morpho- 

 logically constitutes the true gill, is attached to the outer 

 side of the stem, at some distance from the exopodite, and 

 has the form of a comparatively small sac-like lamella, 

 without any setous armature, but of a peculiarly spongy 

 structure. Just above this lamella the basal plate issues with 

 a broad base from the stem. It is very thin and pellucid, 

 oval, or elliptical in form, and has the edges perfectly smooth. 



The 1st pair of legs (fig. 9), as above stated, are much 

 smaller than any of the others, and have also the exopodite 

 comparatively less fully developed. In the 11th, or last 

 pair (fig. 11) the terminal lobe of the endopodite is less 

 broad than in the other pairs, being almost cordate in form; 

 and the setæ of the inner lobules are much reduced in 

 number, and are rather short. The epipodite has lost its 

 branchial structure, and assumed the character of a simple 

 plate, the terminal edge of which exhibits a number of 

 coarse serrations. The basal plate is fully as large as in 

 the other pairs. 



The marsupial pouch (see fig. 1), as above stated, is 

 very slender and elongated, almost cylindric in form, though 

 terminating- in an acute point, which forms one of the lips 

 defining the valvular opening, through which the ova are 

 expelled. 



