Jordan and £vermann. — Fis/tes of JVorth America. 547 



rods, which form a complicated apparatus, destined nndoubtciUy to pro- 

 duce an image and to receive especial luminous rays." * 



Bones of lower part of head well ossified, mouth wide, the lower jaw 

 projecting, and the maxillary dilated, as in Bath\ji)tero\s. Jaws with nar- 

 row bauds of villiform teeth, none on vomer or palatines. None of the 

 fins filamentous ; pectorals and ventrals near together, well developed. 

 Dorsal inserted just behind vent ; no adipose fin ; anal moderate ; caudal 

 subtruncate. Gill rakers needle-shaped. No air bladder, psendobranchiie, 

 nor pyloric cceca. One species known, widely distributed. (Invuc, lantern ; 

 (JV, eye.) 



824. IPNOPS MURRATI, GUnther. 



Head 6; depth 13i. D. 10; A. 13; P. 14; V. 8; B. 12; scales 55, Body 

 very slender; head much broader than deep, the snout much depressed, 

 its outline obtusely rounded ; maxillary extending beyond middle of head. 

 Gill rakers 10 + 22, long and close-set. Vent between ventral fins, slightly 

 more than a head's length behind gill opening, and nearly twice as far 

 from base of caudal as from tip of snout. Caudal subtruncate ; pectoral 

 reaching ventrals, a little more than half head ; ventrals rather long, 

 stronger than pectorals and placed well apart. Lateral line faintly indi- 

 cated. Brown, fins colorless; membranes of mouth aiid gill cavity black. 

 Length 5i inches. A bottom fish found at about 2,000 fathoms, recorded 

 from coast of Brazil, Tristan da Cunha, Celebes, and in tropical America, 

 (24° 36' N., 84° W.), and off Bequia. (Named for Dr. John Murray, natu- 

 ralist on the Challenger e^iiedition.) 



Ipno2)S mnrrmji, GvnTHER, Ann. Mag. Nat. Hist., 1878, ii, 187, coast of Brazil, etc.; Gi'N- 

 THER, Voyage Challenger, Deop-Sea Fishes, 191, 1887; Agassiz, Cruises of the Blake, ii, 'A2, 

 fig. 215, 1888; GoODE & Bean, Oceanic Ichthyology, 67, 1895. 



Family LXXIII. RONDELETIID^. 



Body more or less compressed, scaleless ; head naked ; no barbels ; 

 mouth large. Margin of the upper jaw formed by the premaxillaries 

 only. Teeth coarsely granular. Opercular apparatus complete, its bones 

 very thin, membrane-like ; no adipose fin ; dorsal fin far back, short and 

 low, inserted opposite the anal; pectorals short, placed rather low. 

 Ventrals present, abdominal. Gill opening very wide ; membranes deeply 

 cleft, free from the isthmus. PseudobranchiiB absent. Deep-sea fishes. 

 One species known. (Goode & Bean.) 



{Rondeletiiihc, Goode & Bean, I'roc. U. S. Nat. Mus., 1894 (1.S95), 454, and in (Jceauic Ichtliyology, 

 67, 1895.) 



*" The existence of well-developed eyes among fishes destined to live in the dark aby.«ses of 

 the ocean seems at first contradictory, Ijut we must remember that these denizens of the deep 

 are immigrants from the shore and from the surface. In some cases the eyes havt- not been 

 specially modified, but in others there have been modifications of a luminous mucous luem- 

 'brane, leading on the one hand to phosphorescent organs more or less specialized, or on the other 

 tosucli remarkablestruetures as the eye.s of Ipiiops, intermediate between true eyes and Bpecialized 

 phosphorescent plates. In fishes that have been blinded and retain for their guidance only the 

 general sensibility of the integuments and of the lateral line, these parts soon acquire a very 

 great delicacy. The same is the case with tactile organs (as in B(i%;)/en)is and Hentliosaiinis), 

 and experiments show that barliels may lieconn^ organs of touch adapted toaciuatic life, sensitive 

 to the faintest movements or the slightest ilis]ilncement, with power to give the blinded fishes 

 full cognizance of the state of the medium in which they live." — Alexauder Aijassiz. 



