THE CODFISHES 



Family LXXI. Gadida 



BODY more or less elongate, the caudal region moderate, 

 coniform behind, and with the caudal rays procurrent above and 

 below; vent submedian; scales small, cycloid; mouth large, ter- 

 minal; chin with a barbel more or less developed; gill-openings 

 very wide; gill-membranes separate or sometimes united, com- 

 monly free from the isthmus; no spines in the fins, the rays all reticul- 

 ated; dorsal fin extending almost the whole length of the back, 

 forming i, 2 or 3 fins; anal fin long, single or divided; caudal 

 fin distinct, or confluent with the dorsal and anal; ventral fins 

 jugular, each of I to 8 branched rays; no pseudobranchiae; air- 

 bladder generally well developed. 



This is a large family with about 25 genera and 140 species, 

 many of which are highly valued as food. They inhabit chiefly 

 the northern seas, sometimes venturing into oceanic abysses. 

 One genus (Lota) is confined to freshwater lakes and streams. 

 In American waters we have about 36 species representing 19 

 genera, of which only the following contain food-fishes of any im- 

 portance to us. 



a. Anal divided into 2 separate fins, the dorsal into 3. 



b. Lower jaw distinctly projecting; barbel small or obsolete; 



caudal concave. 



c. Subopercle arid postclavicle normal, both thin and flat, not 



enlarged and ivory-like ; Pollachius, 509 



cc. Subopercle and postclavicle enlarged, the bone dense and 



smooth, like ivory ; Theragra, 5 10 



bb. Lower jaw included; barbel well developed; caudal not concave. 



d. Lateral line pale; supraoccipital crest moderate. 



e. Vent in front of second dorsal; size very small;. ..Microgadus, 51 1 

 ee. Vent below second dorsal; typical codfishes of large size; 



Gadus, 5 1 2 

 dd. Lateral line black; supraoccipital crest very high; 



Melanogr animus, 5 1 6 



aa. Anal forming a continuous fin or sometimes deeply notched; 

 dorsal not divided into 3 fins. 



/. Ventral fins rather broad, each of about 6 rays; Lota, 517 



ff. Ventral fins very slender, each with i to 3 rays ; . . Urophycis, 518 



508 



