704 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



of length; ventral fins short. Head G; depth 10. Gulf Stream, oif the 

 coast of Florida. (Gill.) 

 (Leptophidiumprofundorum Gill, Proc. Acad. Nat. Sci. Phila. 1803, 211.) 



FAMILY CXX. GADID^.* 



(The Cod-fishes.) 



Body elongate, more or less compressed behind ; tail usually isocer- 

 cal (diphycercal in Dinematichthys); scales cycloid, small, sometimes 

 wanting. Grill-openings very wide; gill-membranes separated or some- 

 what united, commonly free from the isthmus; no spines, the fin-rays 

 all articulated. Dorsal flu exteuding almost the length of the back, 

 forming one, two, or three fins; anal fin long, single or divided; caudal 

 h'n distinct, or continent with the dorsal and anal; ventral fins jugular, 

 but attached to the pubic bone, each of one to eight branched rays. 

 Gills 4, a slit behind the fourth. No pseudobrauchisB. Edge of pre- 

 opercle usually covered by skin of head. Pyloric cceca usually numer- 

 ous, but sometimes few or none. Air-bladder generally well developed. 

 Genera 35, species about 90; an important family, many of its members 

 being highly valued as food. They inhabit chiefly the northern seas; 

 one genus (Lota) being confined to the fresh waters. Two genera (tity- 

 yicola, Lucifitga) are blind and inhabit the cave streams of Cuba. 



(Gadidcc Giinther, iv, 326-369; Ophidildai, group Urolulina, iv, 371-376.) 



a. Body scaly. 



b. Vertical fitis united or approximated ; pyloric coeca two ; no barbel. (Brolulinw.) 



c. Vertical fins united BYTHITES, 434. 



<-. Vertical tins separate ; tail diphycercal DIXEMATICHTHYS, 435. 



bb. Vertical tins well separated; pyloric co3ca mostly numerous; tail isocercal. 

 (I. Frontal bone single, normal, ((ladnnt'.} 



e. Anterior dorsal composed of a band of fringes preceded by a slender ray; 

 barbels 3 to 5. 



/. Ventral rays 3 to 5; anal ii'n entire ONOS, 436. 



ee. Anterior dorsal composed of distinct, rays. 

 g. Chin with ;i barbel. 



h. Dorsal (ins two; anal fin one. 



i. Ventral tins narrow, filamentous, each composed of two ov three 



slender rays PilYcis, 437. 



il. Ventrals broader, each of about si\ rays. 



j. Tail attenuate ; anal tin notched ; month inferior: deep-sea (ishes. 



1 1 \ i.or<>i:riiYi:rs, 4:!.-. 

 jj. Tail normal ; anal tin entire : mouth terminal. 



A". Vomer toothless; teeth \illiform PllYSlt'ULrs, 439. 



/,/,. Yonier with teeth. 



7. Vomer and mandible with canines Mor.VA, 440. 



//. Vomer and mandible without canines LoTA, 441. 



'Including family 119, Jirotiilida;, in the key to the families, page 79. 



