8 G. O. Sars. 



in the two sexes, though perhaps a little longer in the male, 

 where they equal the length of the last 3 caudal segments 

 combined. They are (see fig. 10) narrow lanceolate in form 

 and but slightly diverging, being fringed all round with uni- 

 form plumose setæ. 



The compound eyes are of moderate size, and of the 

 usual claviform shape. The simple eye, or ocellus, is trace- 

 able in its usual place. 



The antennulæ likewise do not exhibit any peculiarity 

 in their structure. 



The antennæ, as usual, are very different in the two 

 sexes. In the female (fig. 1) they are comparatively small, 

 blade-like, and have the tip rounded off, without any distinct 

 apical lappet. In the male (fig. 2) these appendages attain 

 quite an enormous size, even considerably exceeding half 

 the length of the body. They are, as usual, generally re- 

 curved beneath the anterior part of the body, forming a 

 slight sigmoid flexure ; but being very mobile, they admit, in 

 the living animal, of being stretched out from the body at 

 any angle. As in the other species of this genus, they each 

 (see fig. 4) consist of 3 successive sections, a basal, a median, 

 and a terminal, the last especially being of a very com- 

 plicated structure. The basal section is rather thick and 

 muscular, and is slightly curved. It carries at the end inside, 

 the usual claw-shaped spine, and moreover, opposite this 

 spine on the outer side, a transverse row of 4 digitiform 

 processes of somewhat unequal length and curving down- 

 wards, each terminating in an acute point, and clothed along 

 the concave edge with small dark-coloured papillæ (see fig. 6). 

 The median section is about the length of the basal one, 

 but considerably narrower and very flexible. It is closely 

 annulated transversally, and carries a row of slender spines 



