179 



Gill-openings very -wide below, contracted above, where they do not surpass 

 the level of the pectorals. GiU-covers apparently complete ; their constituent 

 bones, including the branchiostegal rays, though well calcified, are extremely 

 thin and fragile, and are completely concealed within a continuous fold of skin 

 and mucous membrane. Four gills, with narrow lamina and coarse lamella ; 

 the fourth gill-cleft wide ; gill-rakers well developed on all the arches, moder- 

 ately long on the first, short on the fourth and fifth. Pseudobranchi^ rudi- 

 mentary, consisting of four or five delicate short lamella on each side. 



Body covered with minute, hardly imbricate, cycloid scales, about 75 by — 

 of an inch respectively in the shortest and longest diameters. The lateral line 

 traverses the middle of the body uninterruptedly. 



The dorsal fin begins slightly in advance of the posterior fourth of the body 

 measured without the caudal ; the length of its base is shorter than the snout ; 

 its rays, like those of the anal, increase gradually in length from before back- 

 wards, the longest being not quite equal to the major diameter of the eye-ball. 

 The anal begins an eye-length behind the middle of the body as above limited, 

 and ends a short distance behind the last dorsal ray ; its longest rays slightly 

 exceed the longest dorsal rays. Caudal symmetrically forked, its rudimentary 

 rays very numerous, both dorsally and ventrally. Pectorals narrow, rather 

 more than - of the head in length. Ventrals short, arising immediately behind 

 the middle of the body, as above limited, and reaching just behind the vent. 



Stomach subsiphonal ; intestine long, coiled in a spiral ; four small pyloric 

 ca3ca, arranged in a ring. Reproductive glands very large, apparently discharg- 

 ing in the male through a well-developed post-anal papilla. 



Colours in the fresh state : — head snow-white, iris black, body chocolate, 

 fins blackish grey ; mouth, gill-chamber and entire peritoneum intense black. 



One specimen, apparently a male near maturity, measuring 11 inches in 

 length. 



Arabian Sea, near the Laccadives, 1000 fathoms. 



Regd. No. 12872. 



-a"- 



Xenodermichthys, Giinther. 



Xenodermirhthys, Gunther, Ann. Mag. Nat. Hist., 187S, II., p. 250, and Challenger Deep-Sea Fishes, p. 230: 

 <ioode and Bean, Oceanic Ichthyology, p. 46. 



Body low, rather elongate, compressed, without true scales, but with 

 numerous tiny more or less regularly arranged nodules which are probably 

 luminous in function, and often also with scattered rudimentary scales. Mouth 

 small, or moderate, with feeble jaws and small teeth in the premaxilla, ma.xilla, 

 and mandible. Palate toothless. 



Gill-opening wide. Pseudobranchite present. GUI-rakers long and numerous. 



