546 Bulletin 47, United States National Museum. 



one from Station 121, at a depth of 500 fathoms. Other specimens obtained 

 by the Blake off St. Vincent, and by the Albatross at Station 2385, in 740 

 fathoms, and at Station 2117, in 683 fathoms, (quadrifilis, having four 

 threads.) 



Bathypterois quadrifilis, GUNTHER, Ann. & Mag. Nat. Hist., 1878, IT, 184, off coast of Brazil, in 

 500 to 770 fathoms; GOODE & BEAN, Oceanic Ichthyology, 65, fig. 75, 1895. 



823. BATHYPTEROIS LONGIPES, Giinther. 



B. 12 ; D. 13 ; A. 10 ; P. II, 7 or 8 ; V. 8 ; scales 6-55-8. Uppermost pec- 

 toral ray strongest, about as long as the whole fish, bifid toward its 

 extremity ; outer ventral rays much prolonged, strong, but not dilated 

 at the extremity ; dorsal fin inserted at some distance behind root of ven- 

 trals ; adipose fin present or absent. 



Similar to Bathypterois longifilis, differing in the following points : Eye 

 minute ; dorsal fin farther backward, its origin being nearly midway 

 between end of snout and root of caudal ; consequently the root of the 

 ventral is some distance in advance of the dorsal, and the end of the dorsal 

 is vertically opposite fifth anal ray. One specimen possesses, the other 

 lacks, adipose fin. Caudal fin deeply forked, with the outer ray much 

 produced. Of the two branches into which the posterior third of the 

 long pectoral ray is split, one is much shorter and weaker than the other. 

 Two outer ventral rays ai e closely appressed from the root to end, and 

 much stouter and longer than the other rays ; they are articulated to the 

 end and without soft pads. These fin rays extend beyond the end of the 

 anal fin. (Giinther.) Color black, with white fins. 



The Challenger obtained two specimens, 9 inches long, from off" the east 

 coast of South America, Station 325, depth 2,650 fathoms. Several 

 specimens, 3 to 9 inches long, were obtained by the Albatross and the 

 Slake. (longuSjlong', pes, foot.) 



Bathypterois longipes, GUNTHER, Ann. Mag. Nat. Hist., 1878, u, 184, east coast of South 

 America in 2,650 fathoms; GUNTHER, Challenger Report, xxu, 188, pi. 48, fig. A, 1887; 

 GOODE & BEAN, Oceanic Ichthyology, 66, fig. 76, 1805. 



Family LXXII. IPNOPID^E. 



The characters of this singular group of deep-sea fishes are included 

 below in the account of the single genus. 



254. IPNOPS, Giinther. 



Ipnops, GUNTHER, Ann. Mag. Nat. Hist., 1878, n, 187, (murrayi). 



Body elongate, subcylindrical, covered with large, thin, deciduous 

 scales, and without luminous organs. Head depressed, with a long, thin, 

 spatulate snout, like that of Bathypterois, but more depressed, its whole 

 upper surface occupied by a pair of large, transparent, lamelliform mem- 

 brane bones which cover a peculiar organ divided longitudinally into two 

 symmetrical halves. These organs, which represent the eyes, were at 

 first supposed to be luminous organs, but according to recent investiga- 

 tions of Professor Moseley they " show a flattened cornea extending along 

 the median line of the snout, with a large retina composed of peculiar 



