646 CRUSTACEA. 



parts thickest ; n, liver and duct ; n', section of same ; o, posterior 

 branchia ; o', extremity of setiform branchlet, more enlarged. 



Antarctic Seas, south of Van Diemen's Land, latitude, 66 05' 

 south, longitude 157 east, where it was obtained by Lieutenant 

 Totten, U. S. Ship Porpoise. 



Length, two inches. Colour, as noted and sketched by Lieutenant 

 Totten, red, spotted with whitish. Body compressed, smooth, naked. 

 Eyes large, globular, on short peduncles. Base of inner antennae 

 longer than base of outer ; third joint shorter a little than second ; 

 flagella about half as long as the body, shorter than flagellum of outer 

 antennae ; third joint of base of outer antennae longer than fourth 

 (or last) ; flagellum slender, naked, more than half the length of the 

 body. Hairs of legs, as in other Euphausiae, extremely slender. 



Branchise attached to all the legs excepting first pair. The anterior 

 consist of a lunate plate attached by a pedicel, proceeding from the 

 concave side of the truncate plate at the base of the legs. The two 

 posterior pairs of branchiae (the legs corresponding to which are want- 

 ing) have the basal plate spirally curved (fig. o), and the circum- 

 ference bears a series of radii, which are themselves incurved at apex, 

 and bear each a series of slender setae, increasing in length from 

 behind forward. On the anterior side of the basal portion, near its 

 insertion, there is a long slender branch, which bears branches on its 

 sides, and these branches are furnished with a row of setiform branch- 

 lets like t he other . 



The first two pairs of abdominal legs are unlike the following and 

 dissimilar. The outer branch has the usual form; the inner and 

 smaller of first pair consists of three portions, as in figure h, which are 

 generally folded together; the inner portion has the ordinary cha- 

 racter of this branch, being an oblong ciliate lamella ; the next has a 

 short, stout hook below the apex ; the third has an oblong curved 

 process a short distance from the apex, and at the apex it bears a 

 stout, oblong, slender organ, which appears to be tubular. 



The mandibles have a denticulate apex, and a three-jointed palpus 

 inserted near the summit. The maxillae are broad lamellar in form, 

 and consist of three plates, the basal largest,, the whole together 

 looking like a lobed leaf. The maxillipeds consist of four lamellar 

 joints, and are somewhat oblong triangular in form ; on the outer side 



