42 Till!: VOYAGE OF H.M.S. CHALLENGER. 



tLe dorsal crest, and even a short distance back on its base. The supra-orbital spines 

 are rather smaller than in Gnathophausia ivillemoesii, and more divergent, scarcely 

 projecting beyond the eyes. No distinct antennal nor branchiostegal spines are present, 

 the lateral expansions of the carapace forming in lieu thereof only two slight angular 

 projections. 



The ■ caudal segments do not exhibit any trace of a dorsal keel, nor does their 

 posterior margin form any dorsal projections. The epimera are very small, scarcely 

 projecting even beyond the ventral face, and their posterior lappet is obtusely rounded at 

 the tip. 



The eyes are nearly of the same form as in Gnathojyhausia ivillemoesii. 



The antennal scale (see fig. 9) is rather large, but comparatively not so broad as in 

 the preceding species ; its terminal lobe, too, is more produced, and projects very 

 considerably beyond the spine of the outer corner. 



As regards the oral appendages, the legs, and the caudal limbs, I need not dwell on 

 the description of these parts, as they are much the same in all species belonging to this 

 section. 



Moreover, the telsou and uropoda (see fig. 10) do not exhibit any essential diiference 

 from the same parts in Gnathophausia willemoesii, excepting, perhaps, that the lateral 

 margins of the telson are somewhat more strongly arched in the distal part, and that the 

 apical spines have a short denticle at the outer edge. 



Habitat. — The specimen described above was taken in the tropical part of the 

 Atlantic, almost midway between Africa and Brazil. 



Station 107, August 26, 1873; lat. 1° 22' N., long. 26° 36' W.; depth, 1500 fathoms; 

 (jtlobigerina ooze; bottom temperature, 37''"9. 



8. Gnathojjhausia elegans, G. O. Sars (PI. VI. figs. 1-5). 



Gnathophausia elegans, G. 0. Sais, Preliminary Notices on the Challenger Schizopoda, No. 8. 



Specific Characters. — Form of body very slender. Carapace not completely covering 

 the last segment of the trunk, and wanting the upper lateral keel ; the cardio-branchial sulcus 

 distinctly marked. Dorsal spine of moderate length, reaching to the end of the second 

 caudal segment. Rostrum rather elongate, equalling the carapace in length, and distinctly 

 denticulate throughout. Supra-orbital spines well marked, though not very strong; 

 antennal spines exceedingly small; branchiostegal spines wanting. Caudal segments 

 rather slender, not keeled above ; epimera small, with the posterior lappet but slightly 

 projecting. Antennal scale with the spine of the outer corner smooth, and projecting a 

 trifle beyond the terminal lobe. Telson linguiform, the apical spines very short, and 

 .separated by a denticulated cleft. Length, 56 mm. 



Remarks. — This is a very fine and elegant species, somewhat resembling Gnatho- 



