DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 55 



rior profile and trausvorso anterior mouth, the cleft of tlie mouth being nearly on the same 

 level as the lower uiargiu of the eye. All the bones of the head are very thin, seniicarti- 

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

 opening beginning opposite to the root of the j)ectoral 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 brauchiostegals 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 c()m])osed of feeble rays. Vent placed far l)ackwards, the length of the tail 

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

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

 ascertain its shape. I'ectoral fin narrow, close to the lower profile. Ventrals opposite to 

 the hind i)art of the dorsal fin. 



All the scales being lost, their size and number can be given only approximately fi'om 

 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 tlie color nothing can be stated, 

 except that the scale i)ouches have a distinct black margin. (Criinther.) 



liadial formula: B. 3; D. 9; A. 13; P. 7; V. S; L. lat. -10. 



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

 in the South Atlantic, at station 31S (depth, 2,04:0 fathoms). 



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

 Challenger Report, xxii, 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 (equal 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; 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 liom the end of the base of the 

 dorsal being greater than the length of the head. 



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



Several specimens were obtained by the Alhafross: one (No. 35420, U. S. N. M.) in 39° 

 29' N. lat., 71° 46' W, hni., at a depth of 693 fathoms; another (No. 31861, U. S. N. M.)in 

 39° 52' N. lat., 70° 30' W. h)n., at a depth of about 600 fathoms ; a third (No. 39477, U. S. N. M.), 

 a small indiv^idual, 4 inches in length, in bad condition, wliich appears to belong to this 

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

 fathoms. 



BATnYLAGtlS BENEDICTI, Goode and Bean, n. s. (Figure 64.) 



This species is in some respects intermediate between 7>. (ithinticus and B. 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 

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

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

 brauchiostegals as in the other species. The origin 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. Tent placed farther for- 



