Jheringula pauleiisis, a new generic Type of Macrothricidæ. 15 



only along the one edge. The posterior set only contains 

 2 setæ of exactly the same structure as those of the middle set, 

 and, like the latter, having inside them a short dentiform 

 prominence. Immediately above the masticatory lobe, a single 

 plumose seta issues from the stem, pointing backwards. Out- 

 side the proximal part of the stem, a vesicular body is at- 

 tached, evidently representing the epipodite, and answering 

 to the true gills in higher Crustacea. This appendage is 

 somewhat fusiform in shape, being drawn out into 2 oppo- 

 site narrow lappets, the posterior of which is peculiarly 

 twisted and, as it were, doubled upon the median part. The 

 endopodite is rather short, and forms the immediate con- 

 tinuation of the stem, though it is well defined at the base. 

 It somewhat tapers distally, and consists of 2 imperfectly 

 defined joints, the last of which carries on the tip 3 claw- 

 like spines, rapidly increasing in size outwards, the outer- 

 most spine being fully twice as long as the innermost. All 

 3 spines are distinctly biarticulate and coarsely ciliated along 

 their concave edge. Outside this part, an oblong lamella 

 is movably attached to the end of the stem, carrying a very 

 long apical seta, and a much shorter lateral one. The apical 

 seta is distinctly biarticulate, with the distal joint coarsely 

 ciliated along one of the edges, and generally projects below 

 beyond the valves (see PI. I, fig. 1). This lamella un- 

 doubtedly represents the exopodite, and it will be found, 

 though very much transformed, in the same place also on 

 the 3 succeeding pairs. 



The 2nd pair of legs (fig. 7) are somewhat smaller than 

 the 1st, but are very strongly built, and, like the latter, have the 

 stem bent in a geniculate manner, the anterior margin form- 

 ing an angular protuberance clothed with fine hairs. At 

 some distance below this bend, the stem is crossed by a 



