602 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
MACR0URID£. a 
By David Starr Jordan and Charles Heniy Gilbert. 
Body elongate, tapering into a very long compressed tail, which ends in a point; scales moderate, 
often keeled or spinous, sometimes smooth. Suborbital bones enlarged, usually cavernous. Teeth 
villiform or cardiform, in bands or single series, on jaws only; tip of lower jaw usually with a barbel; 
premaxillary protractile. Dorsal fins 2, the first short and high, its second ray usually stiff and spine- 
like, the others branched; the second dorsal very long, usually of very low feeble rays, continued to 
end of tail; anal fin similar to second dorsal, but usually much higher; no caudal fin; ventrals small, 
subjugular, each usually of about 8 rays. Branchiostegals 6 or 7. Lateral line present. Gills 3.5 or 
4, usually but not always with a slit behind fourth. Gillrakers small ; gill-membranes free or narrowly 
united to isthmus, usually more or less connected; pseudobranchise wanting or rudimentary; pyloric 
cajca numerous; air-bladder present. Hypercoracoid usually without foramen. 
Genera 18; species about 50, chiefly of the northern seas, all in deep water. They differ from the 
cod-fishes chiefly in the elongate and degenerate condition of the posterior part of the body. Dr. Gill 
succinctly defines the group as “Gadoidea with an elongated tail tapering backward and destitute of a 
caudal fin, postpectoral anus, enlarged suborbital bones, inferior mouth, subbrachial ventrals, a distinct 
anterior dorsal, and a long second dorsal and anal converging on end of tail.” 
I. Bathygadin,E; First branchial arch free, without fold of membrane across it; mouth large; second dorsal well 
developed. 
a. Gills I, a slit behind the fourth; no elevated anterior lobe to anal fin. 
b. Coracoid foramen entirely within the hypercoracoid, as in blennoid fishes. 
c. Barbel well developed Gadomus 
cc. Barbel none Regania 
b. Coracoid foramen between the hypercoracoid and hypocoracoid; skull papery; gill membranes jet black. 
Mei.anobkanchus 
II. Macrourin.'e. First branchial arch with a fold of membrane across its terminal portion; gills 4; a slit 
behind the fourth; foramen, so far as known, between the hypercoracoid and hypo- 
coracoid; chin with a barbel, which is rarely minute or absent, 
r. Teeth not all in villiform bands; those of the lower jaw in a single series; mouth rather large, more 
or less lateral. 
d. Upper jaw without a villiform band behind the anterior teeth; inner teeth, if present, chiefly in 
one series. 
e. Dorsal tins widely separated, interspace greater than base of first; dorsal spine serrate, scales 
nearly smooth, the ridges not spiniferous Dolloa 
dd. Upper jaw with a villiform band behind outer series of enlarged teeth; scales cycloid, smoothish. 
/. Dorsal spine serrate; dorsal fins not widely separate Chalinura 
ff. Dorsal spine smooth; dorsal fins well separated; pectoral fin elongate Abyssicoi.a 
cc. Teeth in villiform bands above and below, the outer like the rest and scarcely enlarged or separated; 
lower band sometimes reduced laterally to a single series. 
g. Mouth wide, with considerable lateral cleft. 
h. Dorsal spine finely barbed; bones of skull rather firm; dorsals moderately separated . . .Coryphjenoides 
hh. Dorsal spine entirely smooth; bones of skull very thin and papery; dorsals well separated; 
barbel small or absent Hymenocephalus 
gg. Mouth small, inferior, with little lateral cleft; suborbital ridge usually prominent. 
i. Scales spinous, very rough. 
j. Scales distinct, regularly imbricated. 
k. Ventral rays 7 to 10. 
I. Dorsal spine serrate; snout short Macrourcs 
II . Dorsal spine entire; snout produced, sturgeon-like Ccelorhynchus 
kk. Ventral rays 13 to 15 Nezumia 
jj. Scales indistinct, scarcely imbricated, the whole body rough-villous; dorsal spine smooth. 
Trachonurus 
a In the account of this family all the Macrouridse known from Japan are treated. 
