12 Gr. O. Sars. 



short articulations, minutely spinous at the end. The 4th endite 

 is much the longest, nearly equalling in length the whole 

 stem, and, together with the 3rd, is often seen projecting 

 beyond the edge of the carapace, Avhen the animal is viewed 

 dorsally (fig. 1). As is well known, these endites are in the 

 genus Apus distinguished by their great length, whereas in 

 the genus Lepiduriis they are generally much shorter. In the 

 present species they are comparatively longer than in most 

 other species of the genus. The epipodite is very minute, 

 and the exopodite is also much smaller than in the succeeding 

 pairs, and of a triangular form, being drawn out to two oppo- 

 site lobes of about equal size, the lower one setous at the 

 edge. 



The 2nd pair of legs (fig. 9) are much more strongly built 

 than the 1st, and have the endopodite very distinctly bent on 

 the middle. The segmentation of the latter is well marked, 

 and the coxal lobe rather strong, almost cordiform in shape. 

 The endites differ rather conspicuously from those in the 1st 

 pair, being much shorter and coarser, almost claw-like in 

 character, and slightly serrated on the inner edge, but not 

 distinctly articulated. The 4:th endite is also in this pair the 

 largest, though scarcely attaining half the length of the endopo- 

 dite. The 5th endite is well developed, and exhibits the form 

 of a movable claw, somewhat shorter than the preceding endite 

 and finely setous along its outer edge. The epipodite as also 

 the exopodite are comparatively larger than in the 1st pair, 

 though otherwise of a very similar appearance. 



In the 7 succeeding pairs there is a very gradual transi- 

 tion to the structure found in the 10th pair. 



The latter (fig. 10) are, as compared with the 2nd, chiefly 

 distinguished by the circumstance of the endopodite being con- 

 siderably abbreviated, much less curved, and also devoid of 

 any distinct segmentation. The endites have assumed the form 

 of broadly lanceolate lappets slightly serrated at the distal part 



