148 THE VOYAGE OF H.M.S. CHALLENGER. 



Description. — Several, but the greater part defective, specimens of this striking form 

 are met with in the collection, the largest of wliic^li has a length of 8 mm. All 

 si:)ecimens would seem to be females. 



The form of the body (see PI. XXVII. fig. 11) is exceedingly short and thickset, 

 more so perhaps than in any other known species of Euphausiidae. 



The carapace, in particular, is remarkably shortened, almost as high as long, and 

 al)ove has a distinct, though not very elevated, rounded crest. The rostral projection 

 is rather strong, lanceolate, and terminates in a, very acute and somewhat deflexed 

 point. 



The five anterior caudal segments are somewhat thick, and furnished with compara- 

 tively small, rounded epimera. The last segment, on the other hand, is very elongate 

 and tapers toward the apex. Of the preanal spine, no trace whatever could be 

 detected. 



The eyes are prodigiously developed, with very thick, and, as it were, swollen 

 pedicles, and the cornea somewhat expanded below but apprecial)ly narrowed in the 

 upper part. 



The antennular peduncle is rather elongate, with the two outer joints very slender 

 and about equal in length. Both of the flagella were broken in all the specimens. 



The antennal scale (fig. 12) is rather large, reaching to well nigh the middle of the 

 last joint of the antennular peduncle; it exhibits a narrow, linear form, being somewhat 

 curved and narrowly truncate at the apex, with the outer corner projecting as a small 

 denticle. The flagellum is very slender, with its basal part exceedingly narrow and 

 projecting far beyond the tip of the scale, having also the middle joint by far the 

 longest. 



The second pair of legs (see fig. 11) do not attain, when fully extended, the length 

 of the body, and have the carpal joint scarcely more than half as long as the meral. 

 The propodal joint, on the other hand, is more produced than in any of the preceding- 

 species, attaining well nigh the length of the carpal, and juts out at the end interiorly 

 as a strong unguiform spine. The last joint is digitiform -produced, and terminates in a 

 strong incurved claw, lieariug at its base two secondary spines. This joint, too, admits 

 of being impinged against the sjiine arising from the preceding joint, and thus consti- 

 tutes with the latter a complete chela, in appearance somewhat resembling that in 

 several Decapods. 



The caudal fan does not exhibit any marked peculiarities. The inner plate of the 

 uropoda is, however, somewhat longer than the outer, and projects a little beyond the 

 tip of the telson. 



Habitat. — The specimens were taken at the surface of the soa, in the following 

 localities : — 



