DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 55 



rior profile and transverse anterior mouth, the clefl of the moutb being nearly on the same 

 level as the lower margin of the eye. All the bones of the head are very thin, semicarti 

 laginons; the head seems to have been scaleless. The gill cavity is closed behind, the gill 

 opening beginning opposite to the runt of the pectoral fin, and the gill membrane forming a 

 broad bridge across the isthmus. This membranous bridge is not attached to the isthmus 

 and contains a layer of transverse muscular fascicles, by which the gill covers can be simul- 

 taneously firmly closed. The branchiostegals are extremely thin and short and hidden in 

 the membrane. The dorsal tin commences nearly midway between the snout and caudal: 

 it is short and composed of feeble rays. Vent placed far backwards, the length of the tail 

 not being- much more than that of the head. Anal lin likewise composed of feeble rays, 

 terminating' at a short distance from the caudal. The caudal tin is too much injured to 

 ascertain its shape. Pectoral tin narrow, close to the lower profile. Ventrals opposite to 

 the hind pari of the. dorsal tin. 



All the scales being lost, their size and number can be given only approximately from 

 the remaining scale pouches; they must have been very thin, and the lateral line seems to 

 have run along the middle of the side of the body. Of the color nothing can be stated, 

 except that the scale pouches have a distinct black margin. ( GHinther.) 



Radial formula: B. 3; D. 9; A. 13; P. 7; V. 8; L. hit. 40. 



One specimen, in very bad condition and 0i inches long, was obtained by the Challenger 

 in the South Atlantic, at station 318 (depth, 2,04(1 fathoms). 



The allied form, Bathylagus antarcticus, Giinther (Ann. and Mag. Nat. Hist.. 1878, n, 248 ; 

 Challenger Report, xxn, 220), was obtained in the Antarctic Ocean by the Challenger, at a 

 depth of 1,950 fathoms. 



BATHYLAGUS EURYOPS, Goode and Bean, n. s. (Figure 63.) 



Height of the body considerably less than the length of the head (ecpral to length of the 

 head without snout), the length of the head being one-fourth of the total (without caudal). 

 The diameter of the eye is one-half the length of the head; width of the interorbital space a 

 little more than one-half the diameter of the eye. Snout very short; steep profile; itsangle 

 on a level with the lower margin of the eye. All the bones of the head very thin, semicar- 

 tilaginous. Gill apparatus as in the other species. Dorsal fin feeble, nearer tip of snout 

 than root of caudal. The vent far back, the length of the 'tail not being much more than 

 that of the head. Anal tin feeble, distance of its insertion from the end of the base of the 

 dorsal being greater than the length of the head. 



Ea.lial formula: D. 19; A. 16; B. 7; P. 9. 



Several specimens were obtained by the Albatross: one (No. 35420, TJ. S. X. M.) in 39° 

 29' N. lat., 71° 40' W. Ion., at a depth of 693 fathoms; another (No. 31861, U. S. N. M.)in 

 39° 52' N. lat., 70° 30' W. Ion., at a depth of about 600 fathoms ; a t bird (No. 39477, U. S. N. M.), 

 a small individual, 4 inches in length, in bad condition, which appears to belong to this 

 species, taken at station 2571 in 40° 09' 30" N. lat., 67° 09' W. Ion., at a depth of 1356 

 fathoms. 



BATHYLAGUS BENEDICTI, Goodk and Bean, n. a. (Fignre 64.) 



This species is in some respects intermediate between B. atlanticus and 1>. antarcticus. 

 The height of the body is nearly equal to the length of the head, which is two ninths of the 

 total (without caudal). The diameter of the eye is one-half the length of the head, as in 

 the other species. The width of the interorbital space is less than two-thirds of that of the 

 eye (proportionately narrower than in the other species). Snout very short, its length 

 about one-fourth the diameter of the eye. Mouth short, its angle being about on a level 

 witli the lower margin of the eye. Bones of head thin, semicartilaginous ; head apparently 

 scaleless; no traces of scales in the specimens before us. dill cavity, membranes, and 

 branchiostegals as in the other species. The origin of the dorsal lin is nearer to the end of 

 the snout than to the base of the caudal, and equidistant between the snout and the adi- 

 pose fin; its length equal to two-fifths of the length of the head. Vent placed farther for- 



