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



The front is not produced below to any rostral prominence, nor is the slightest 

 trace of any tentacular filaments to be detected. 



The tail (fig. 7) is comparatively short, scarcely exceeding in length Va 

 of the anterior division, and is divided into 4 segments, which are very 

 sharply marked off from each other. The 1st, or genital segment, as usual, 

 is the largest, though shorter than the 2 succeeding ones combined, and is 

 but slightly protuberant below. The last, or anal segment is both shorter 

 and narrower than the others, and is somewhat obhquely truncated on each 

 side at the junction with the caudal rami. The latter are very small, lamelli- 

 form, and each carry only 3 plumose setae, 2 of which issue from the tip, 

 the 3rd from a distinct ledge of the outer edge. Of these setae the middle 

 one is the longest, and the innermost the shortest. In addition, the usual 

 unciliated bristle occurs at the inner corner of each ramus. 



No trace of any eye could be detected in the preserved specimens. 



The anterior antennae (fig. 4) are scarcely longer than the anterior 

 division of the body, and are composed of 24 articulations, the last of which, 

 however, is so very small, as easily to be overlooked. They are rather 

 thickly clothed anteriorly with delicate bristles, especially in their proximal part. 



The posterior antennae (PI. XXXI, fig. 1) are normally developed. The 

 basal part is rather thick, and has at the end of the 1st joint a compara- 

 tively short ciliated setae, at the end of the 2nd joint 2 much longer setae. 

 The inner ramus is about twice the length of the basal part, with the proxi- 

 mal joint somewhat compressed, and provided at some distance from the end 

 anteriorly with a short seta. The distal joint, as usual, is lamelliform and 

 unequally bilobed, carrying about 12 slender setae arranged in a flabelliform 

 manner. The outer ramus is about the length of the inner, and is divided 

 into 7 well-defined articulations. Of these the 1st is somewhat larger than 

 the 2nd, with which it is connected along a very oblique suture, and projects 

 at the base anteriorly as a rounded protuberance. The 4 succeeding joints 

 are very small, and combined are scarcely as long as the terminal joint. 

 This ramus carries 3 apical and 5 lateral setae. 



The anterior and posterior lips (PI. XXX, fig. 6) exhibit quite a normal 

 appearance. 



The mandibles (PI. XXXI, fig. 2) are well developed, with the masticatory 

 part somewhat expanded, and divided at the end into several teeth. These 



