DISCUSSION OF SPECIES AND THEIR DISTUIISI'TIOX. 55 



rior profile and transverse anterior moutli, the cleft of tlie inoiitli lieiiiy nearly on tlie same 

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

 laginous; the head seems to have been scaleless. The gill eavity is closed liehind, the gill 

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

 broad bridge across the istlimns. 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 firndy closed. The l)ranchiostegals are extremely thin and short and hidden in 

 the membrane. The dorsal fin 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 fin likewise comi)Osed of feeble rays, 

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

 ascertain its shape. Pectoral fin nari'ow, close to the lower profile. Yeutrals opposite to 

 the hind part of the dorsal tin. 



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

 the remaining scale pom-hes; 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. {Giinther.) 



liadial formula: B. 3; L). 9; A. 13; V. 7; V. S; L. lat. 40. 



One specimen, in very bad condition and 6J inches long, was obtained by the Challenger 

 in the South Atlantic, at stati(m 31S (depth, 2,040 fathoms). 



The allied form, Balliyhtyus antarcticus, Gunther (Ann. and Mag. Nat. Hist., 1878, II, 248; 

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

 depth of 1,950 fathoms. 



BATHYLAGUS EURYOrS, Goode and Bean, n. s. (Figure C:i.) 



Height of th<^ body considerably less than the length of the head (equal to length of the 

 head without snout), the length of the head l)eiug 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 ; its angle 

 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 fin feeble, distance of its insertion fiom the end of the base of the 

 dorsal being greater than the length of the head. 



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



Several specimens were obtained by the Albatross: one (No. 3o420, 17. S. N. M.) in 39^ 

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

 39° 52' N. lat., 70o 30' W. Ion., at a depth of about 600 fathoms ; a third ( No. 39477, TT. 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 deptli of 1356 

 ftxthoms. 



BATHYLAGUS BENEDICTI, Goodf, and Bean. u. s. (Figure fii.l 



This species is in some respects intermediate between B. atlnntiriis and B. antarctictts. 

 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 tlic interorbital space is less than two-thirds of that of the 

 eye (proiiortionately narrower than in the otlier species). Snout very .short, its length 

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

 with the lower margin of tlie eye. Bones of head thin, semicartilaginons; head apparently 

 scaleless; no traces of scales in the specimens before us. Gill cavity, mendn-anes, and 

 branchiostegals as in the other siiecies. The (uigin of the dorsal fin 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, ^'cnt jdaced fiirther for- 



