12 Gr. O. Sars. [No. 4 



to the terminal section. This joint, like the preceding one, is highly 

 chitinized, bnt is scarcely more than half as long, and is oblong oval 

 in form. It gives origin to an exceedingly strong, claw-like spine 

 curving anteriorly, and carries at the end a slender ciliated seta. 

 The 4 outer articulations are of quite normal appearance, the Ist 

 of them being, however, very small and imperfectly defined from 

 the succeeding joint. 



The posterior antennæ, oral parts, and natatory legs do not 

 exhibit any diiference from those parts in the female. 



The last pair of legs (fig. 3), on the other hand, are greatly 

 transformed, and togcther form a very powerful grasping organ. 

 The 2 legs originate from a common base, and are very unequally 

 developed, the right one being more than 3 times as long as the 

 left. Both legs apparently consist of 4 joints, the Ist of which, 

 however, as shown by the seta attached to the outer edge, ought 

 more properly to be referred to the basal part. On the right leg, 

 this joint is prodnced inside to a lanceolate deflexed projection. 

 The 2nd joint of this leg is slightly dilated at the base, exhibiting 

 inside a small rounded lobnle, behind which a short seta is attached. 

 The 3rd joint is somewhat larger than the 2nd, and projects inside 

 at the base to a rather large, linguiform prominence, rounded at 

 the tip and carrying a single seta behind. The last joint has the 

 form of a very long and slender incurved claw, exhibiting, at some 

 distance from the base outside, a knob-like prominence, and inside, 

 somewhat' beyond the middle, a small seta; at the tip, this joint is 

 armed with a short curved spine. The left leg does not exhibit 

 any projections inside, and has the Ist joint somewhat thicker than 

 on the right leg. The 2nd joint is quite simple and slightly curved. 

 The 3rd joint is much shorter than the 2nd, but rather broad, being 

 expanded outside to a rounded prominence, to which a peculiar, soft, 

 transversely rugulose ] am ella is appended (see also fig. 4). The last 

 joint is much more abruptly narrowed than the others, forming a com- 

 paratively small digitiform piece, conspicuously constricted at the 

 base, and terminating in a very acute point; in the middle this joint 

 exhibits an annular instriction, defined by 2 sharp transversal crests. 



