REPOET ON THE SCHIZOPODA. 91 



The uropoda (see fig. 21) have the inner plate much longer than the outer, and, 

 when exserted posteriorly, reaching the tip of the telson. 



Co?ow.r.— According to Dana, the animal, in a fresh state, is quite pellucid, without 

 any distract pigment. 



Habitat. — A good many specimens of the present species were collected by the 

 Expedition in different tracts of the ocean. They were all taken at the surface of the 

 sea. The folloAving is a list of localities, with the dates at which the specimens were 

 obtained :— 



Dana took this form in the Pacific, lat. 15° 23' S., long. 148° 23' W. 

 Distribution. — Hence the species would seem to occur chiefly in the tropical parts of 

 the Atlantic and Pacific Oceans, ranging southward to the Australian Seas. 



22. Euphausia gibba, G. 0. Sars (PI. XVI. figs. 1-8). 



Eupliausia gibba, G. 0. Sars, Preliminary Notices on the Challenger Schizopoda, No. 21. 



Specific Characters. — Form of body very slender. Carapace with a single lateral 

 denticle, placed behind the middle of the inferior margin ; rostral projection acutely 

 pointed. Tail gibbous in the middle, with the third segment projecting, posteriorly, as an 

 acute dorsal lappet, overlapping the succeeding segment. Last segment very elongate ; 

 preanal spine simple. Eyes rather small, slightly expanded at the tip. Basal joint of 

 antenntdse with a very smaE. bifid lappet at the end above. Antennal scale rather large, 

 oblong-ovate, apex obtusely truncate, outer comer unarmed. Telson as in Euphausia 

 gracilis. Iimer plate of uropoda scarcely at all extending beyond outer, and not 

 reaching tip of telson. Length about 1 5 mm. 



Remarhs. — In its external form this species very closely resembles the preceding, 

 but may, on closer examination, be easily recognised by the pecidiar gibbous form of the 

 tad and the dorsal lappet projecting from its third segment. 



Description. — The largest specimens attain a length of 15 mm., and hence the species 

 slightly exceeds the preceding one in size. 



