14 G. O. Sars. 



podite, may be distinguished in all the pairs except the 

 last. But these parts are so variously transformed, that it 

 is rather difficult at first sight to recognize them. In 

 order to show the arrangement of the legs and their mutual 

 relation, I have represented on PI. II, fig. 5, as exactly as 

 possible, the whole left series, as seen under a very high 

 magnifying power from the outer side. Moreover, on the 

 same plate separate figures of a leg of each pair are given 

 (figs. 6—10). 



The 1st pair of legs (fig. 6) are much the largest, and 

 have the stem rather thick and bent near the middle in a 

 geniculate manner, exhibiting in front an angular protuberance 

 clothed with delicate hairs. The masticatory lobe is rather 

 unlike that in the succeeding pairs, extending also somewhat 

 less abruptly inwards, for which reason I have previously, in 

 describing the corresponding leg in Leydigia australis, er- 

 roneously recorded this part as the endopodite. It forms a 

 rounded oval expansion of considerable size extending 

 obliquely inwards and downwards, and carrying on the obtusely 

 rounded extremity several variously formed setæ, which in 

 all specimens are exactly alike, both in number and ar- 

 rangment. There are in all 9 such setæ, besides 2 short 

 dentiform processes. One of the setæ issues somewhat apart 

 from the others, at about the middle of the anterior edge, 

 and is rather strong and curved; the others are arranged in 

 3 successive sets along the terminal edge. The foremost set, 

 occupying the anterior corner, consists of 3 rather short 

 and thick setæ, somewhat increasing in size distally, and, 

 like the seta of the anterior edge, gradually tapering to a 

 'fine point, and densely ciliated on both edges. The middle 

 set consists likewise of 3 setæ, which, however, are of a 

 different structure, being distinctly biarticulate, and ciliated 



