REPORT ON THE SCHIZOPODA. 33 



Habitat. — The above described specimen was obtained l)y the Challenger Expedition, 

 in the vicinity of the Arrou Islands, in the Arafura Sea, lying between New Guinea and 

 Australia. 



Station 191, September 23, 1874 ; lat. 5° 41' S., long. 134" 4' 30" E.; depth, 800 

 fathoms; green mud; bottom temperature, 39°'5. 



The specimen examined by Professor Dohrn, according to the label on the bottle 

 containing it, was procured off the coast of Africa (" Laos ") ; depth not recorded. 



^ 4. Gnathojyhaiisia gigcis, Willemoes-Suhm (PL III.). 



Gnathophausia gl{jas, Suhm, Trans. Linn. Soc. Lond. (Zool.), .«or. 2, vol. i. p. 28, pi. ix. 



figs. 16, 17; pi. X. figs. 2, 3, 1875. 

 Gnathophausia ijigas, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 4. 



Specific Characters. — Form of body (in male) rather more slender than in the last 

 species. Carapace less tumid, having the infero-posterior corners more produced and 

 jutting out into short mucroniform spines, reaching to the end of the second caudal 

 segment. Dorsal spine almost obsolete. Rostrum rather produced and slender, distinctl}- 

 denticulate. Supra-orbital, antenna!, and branchiostegal spines all distinct but small. 

 Caudal segments less distinctly sculptured, the anterior lappet of the epimera small and 

 I'ounded. Epimeral plate of last segment less produced. Eyes narrow, with coi'nea 

 very small. Antehnal scale much larger than in Gnathophausia ingens, and somewhat 

 tapering toward the apex, outer edge divided into four strong teeth, inner corner 

 produced into a rather prominent sharp point. Telson very large, with the lateral 

 margins bulging out in the middle and densely spinulose, terminal spines widely 

 diverging. Length, 142 mm. 



Remarks. — The present species has abeady been briefly described and figured by the 

 late Dr. v. Willemoes-Suhm in the above quoted treatise, and designated by the specific 

 name of " gigas," the preceding still larger form not being known to him at that date. 

 From this latter species it differs, among other characteristics, by the comparativel}' 

 more slender form of the body, the much more produced rostrum, the larger and 

 differently formed antennal scale, and the less completely developed eyes. Moreover, 

 the spines, issuing from the infero-posterior corners of the carapace, are somewhat 

 different in shape, and the sculpturing of the tail is by no means equally conspicuous. 



Description. — Of this species, also, only a solitary specimen in an excellent state of 

 preservation was obtained, viz., a full-grown male, measuring in length 142 mm. As 

 the males of this genus differ l)ut very slightly from the females, it may not unreasonably 

 be inferred that the characters adduced above as specific marks would, on the whole, be 

 no less applicable to the females of this species. 



The form of the body (see figs. 1, 2) is rather more slender than in Gnathophausia 

 ingens, Ijut in this respect, probably some regard should l)e paid to the circumstance 



(zool. chall. EXP. — PART WWII. — 1885.) Oo 5 



