22 G. 0. SARS. CRUSTACEA. [norw. pol. exp. 



specimens, the eyes appear to be altogether wanting, as indicated by M. Chev- 

 reux; but in some of the specimens from the Nansen Expedition, that have 

 been preserved in a weaker solution of alcohol, the ocular pigment was still 

 easily observable, though it had somewhat changed its original colour; and 

 in these specimens the actual presence of eyes, and their enormous size could 

 be proved with full certainty. 



The superior antennae (fig. 4) are comparatively short, about as long as 

 the cephalon and the 2 anterior segments of the mesosome combined, and they 

 exhibit the structure generally met with in the Lysianassidce. The peduncle 

 is short and thick, with the 2 outer joints very small. The flagellum is about 

 twice the length of the peduncle, and is composed of 12 articulations, the 1st 

 of which is rather large, sublaminar, and densely clothed inside with delicate 

 sensory filaments. At the tip, this articulation, like the 3 succeeding ones, 

 carries a rigid bristle. The accessory appendage is fully half the length of the 

 flagellum, and is composed of 6 articulations, the 1st of which is much the large.st. 



The inferior antennae (fig. 5), which issue at some distance below the 

 superior, are about twice as long as the latter, and have the first 2 joints 

 of the peduncle quite concealed by the antero-lateral corners of the cephalon 

 (see fig. 2). The 2 outer joints of the peduncle are of about equal length, 

 and are both clothed anteriorly with short bristles. The flagellum is rather 

 slender, being fully twice as long as the peduncle, and composed of about 30 

 short articulations. 



The buccal mass (see figs. 1 & 2) is greatly protuberant, and wholly 

 uncovered laterally, protruding in front somewhat beyond the anterior edge 

 of the cephalon. The peculiar structure of the mandibles and maxillipeds is 

 easily observable, even without dissection. 



The anterior lip (fig. 6) is comparatively small, exhibiting a median convex 

 part, and 2 rounded lateral expansions. 



The posterior lip (fig. 7) is much larger, with the lateral lobes widely 

 apart, and each projecting behind in a narrow process pointing straight 

 posteriorly. 



The mandibles (fig. 8) are pronouncedly laminar, and without any trace 

 of a molar process^. The cutting edge is quite simple, straight, and sharp, 



' Such a process is certainly described by M. Chevreux; but I believe that in this 

 case he has fallen into an error, by mistaking the chitinous tendon of the rota- 

 tory muscle of the mandible for a process of this kind. 



