606 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Scales large, somewhat more closely adherent than usual, still present over considerable areas of 
body, covering entire head, including mandible and gular region, but not the branchiostegals; scales 
unarmed, finely striated; lateral line runs posteriorly considerably below middle of sides, and rises 
anteriorly in a low convex curve above pectorals; chord of curve equals length of head; 9 or 10 scales 
in an oblique line upward and backward from posterior (submedian) portion of lateral line to base of 
dorsal, 21 scales upward and backward from first anal ray to base of dorsal. 
Color of head and body nearly uniform light grayish, with some silvery luster, breast and belly 
not darker, opercular and gill membranes not black on outer surfaces; symphyseal portion of mandi- 
ble, and corresponding portions of lower lip, dusky; inside of mouth and the gill cavity purplish black; 
posterior margins of opercular and gill membranes irregularly lighter or whitish; fins dusky, dorsal 
and anal blue-black posteriorly. 
Known only from the type. 
MELANOBRANCHUS Regan. 
Melanobranclms Regan, Ann. A Mag. Nat. Hist., 1903, p. 459 (melanobranchus) . 
This genus is closely allied to Bathygadus, differing in the presence of a slit behind the last gill and 
in the absence of barbel. As in Bathygadus, and macrourid fishes generally, the coracoid foramen lies 
between the hypercoracoid and hypocoracoid instead of within the substance of the first-named bone. 
Skull extremely cavernous. Scales weak, caducous. Dorsal fin feeble, the second spine not serrate. 
Gill membranes black. Deep seas. 
(neArts, black; /3payyds, gill.) 
87. Melanobranclms antrodes Jordan & Gilbert, new species. (PI. 4, fig. 1.) 
Type, 265 mm. long (tail slightly injured), from station 3696, Sagami Bay, 501-749 fathoms: 
No. 50932, U. S. Nat. Mus. 
First dorsal ii, 8; ventrals 9; pectoral 14; gill rakers 60-20; branchiostegals 7. Head 4.66 in total 
length. Depth 6.5. 
Very closely related to Melanobranchus bowersi, from vicinity of Hawaiian Islands, differing in the 
lighter color of anterior parts, the slightly firmer consistency of the bones of head, differing propor- 
tions of opercle and preoperele, greater development of upper opercular ridge, and the somewhat smaller 
scales. 
Head very wide, with wide mucous canals and fragile crests; membranes covering the canals 
stronger than usual in this genus, and intact in all the specimens; interorbital width much longer than 
snout or eye, one-third length of head; longitudinal diameter of orbit one-third longer than vertical 
diameter, two-ninths the length of head; snout 3.4 in head, its length equaling its width opposite 
anterior nostrils; posterior border of orbit in middle of length of head; mouth terminal, oblique, 
mandible everywhere included, maxillary everywhere reaching vertical from hinder margin of orbit, 
its length contained 1.86 times in head; no trace of mandibular barbel; teeth minute, equal, with 
narrowly arrow-shaped tips, in a broad premaxillary, and a narrow mandibular band; preoperele 
rather narrow! y rounded, greatest width of its posterior expanded portion, at angle, equaling one- 
eighth length of head; vertical width of suborbital below middle of orbit 5.33 in head; distance from 
hinder margin of orbit to preopercular angle equals less than half length of head; anterior margin of 
nape is slightly nearer tip of snout than front of dorsal; exposed portion of opercle much less in 
proportion to opercular width than in Melanobranchus bowersi. Opercle with two diverging ridges 
ending in weak spines. Above upper ridge is a third much lower ridge, which ends in from one to 
three very we ak spines, nearly as long as the one beneath them. 
Gill-membranes moderately joined, free from isthmus. Four full gills, with a narrow slit behind 
fourth arch; outer gill rakers very long and slender, two-thirds the diameter of orbit (shorter in an 
older specimen). A few unmistakable free pseudobranchial filaments are present, these most abun- 
dant in the largest specimen. Coracoids thin and papery, the foramen lying between the hypercoracoid 
and the hypocoracoid. 
Origin of dorsal is a little in advance of pectorals. All the rays of the vertical fins seem to be 
slender, unbranched. The dorsal rays are injured in the type, but in two cotypes the second ray is 
filamentous, reaching base of eleventh or twelfth ray of second dorsal, and contained 1.71 times in 
head. Dorsals immediately contiguous, rays of second dorsal much higher than anal rays. Upper 
pectoral ray filamentous, reaching as far as base of seventh anal ray, its length four-fifths that of head; 
it is probable that this ray was longer in life; outer ventral ray also very slender and filamentous, 
reaching the tenth anal ray and equaling length of head. 
