DISCUSSION OF SPECIES AM) THEIB DISTRIBUTION. 129 



1 1 'I M an llii S I EEOX, <■' x mi n. (Figure 151.) 



Bathyophi* ferox, GOnther, Ann. and Mag, Nat. Hist. 1878, ii, L81. 



I d i a f mi i luii ferox, G1 mih r, Challengei Report, wu. 216, pi. in, lig. 1>. 



Vent situated at the sixth eighth of the total length. < iommencemenl of the dorsal lin 

 opposite to the root of the ventrals. Black. D. 60; A. 45; V. 6. [Gimther.) 



The Challenger obtained one specimen, 8 inches long, ai station G3, in the middle of the 

 North Atlantic; depth, L.',7.">0 fathoms. 



Order LYOPOMI. 



Lyopomx, Gill, American Naturalist, 1889 (Nov.), 1016. 



Teleosts with the scapular arch constituted by the proscapnla, postero-temporal and 

 post-temporal, the post-temporal discrete from the side of the cranium, and impinging on 

 the supra occipital; the bypercoracoid and hypocoracoid lamellar, and the fenestra or fora- 

 men in the upper margin of the hypocoracoid; the mesocoracoid absent; the actinosts 

 normal; the cranium with the condyle confined to the basi occipital; the opercular appa- 

 ratus characteristic, the preoperculum being entirely detached from the suspensorium, rudi- 

 mentary, and connected only with the lower jaw; the operculum normally connected; the 

 suboperculum enlarged and partly usurping the usual position of the preoperculum, in com- 

 pany with the suborbital chain, which is extended backwards toward the opercular margin; 

 jaw bones complete and normal; palatiues, entopterygoid, and ectopterygoid uormally de- 

 veloped; the anterior vertebrae separate, and the ventrals abdominal. 



Family HALOSAURID^E. 

 Halosaitrido . GirNTHER, Cat, Fish. Brit, Mus., vn, 1868, 482. 



Body covered with cycloid scales; head scaly; barbels none. Margin of the upper jaw 

 formed by the intermaxillaries mesially, and by the maxillaries laterally. Opercular appa- 

 ratus incomplete. Adipose flu none. The short dorsal belongs to the abdominal part of 

 the vertebral column; anal very long. Stomach with a blind sac; intestine short; pyloric 

 appendages in moderate number. Pseudobranchiffl none; air bladder large, simple; gill 

 openings wide. Ovaries closed. 



KEY TO THE GENERA AND SPECIES OF HALOSAURID^E. 



I. Ventrals normal. No second dorsal I'm. 



A. Vertex covered with scales. Scales of lateral line scarcely enlarged. Snout obtusely rounded. Head 



without angular ridges. Ana] comparatively high Halosaurus 



1. Prcoral portion of snout equal to half its length. 



Height of body nearly equal to half length of head and one-seventeenth of total. Diameter 

 of eye two-fifths postorbital portion of head and much greater than width of interorbita] 

 space. About (iO scales in lateral line in front of vent H. Owenii, Johnson 



2. Preoral portion of snout less than half its length. 



Height of body about one-third length of head and one twenty-fifth of total. 



Diameter of eye nearly two-fifths of postorbital portion of head and equal to width of inter- 

 orbital space. About 55 scales in lateral line in front of vent . . . -H. Johnsonianus, Vaillant 



Diameter of eye half length of postorbital portion of head (which is equal to that of snout). 

 and much greater than width of interorbital space. About (37 scales in lateral line in front 

 of vent H. Gf'NTHERl, Goode and Beau 



B. Vertex scaleless. Scales of lateral line enlarged, provided with photophores. Snout pointed. Head 



willi prominent lateral ridges. Anal moderately high, its height one-third to one-fourth of 



ili a i of dorsal Aldrovandia, Goode and Bean 



1. Snout much produced (length equal to or greater than distance from eye to root of pectoral I. 

 a. Preoral portion of snout exceeds half its length. I ii a meter of eye considerably less than width 

 of interorbita] space. Twenty-four scales in lateral line in front of vent. 



A. bostrata i Giinther) 

 irises— No. •> ;i 



