794 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



of length; veutral fins slioit. Head G; depth 10. Gulf Stream, oif the 

 coast of Florida. {Gill.) 

 {LeptopMd'mmprofiuulorum Gill, Proc. Acad. Nat. Sci. Pliila. 1863, 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. Gill-openings very wide; gill-membranes separated or some- 

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

 all articidated. Dorsal fin extending almost the length of the bach, 

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

 fin distinct, or confluent 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 pseudobranchise. 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 {Sty- 

 gicola, Lucifuga) are blind and inhabit the cave streams of Cuba. 



{Gadidw Gnnthiix, iv, 326-369; Ophidiidw, group Brolulina, iv, 371-376.) 



a. Body scaly. 



h. Vertical fiDs united or approximated; pyloric coeca two ; no barbel. (Brotulhicp.) 



c. Vertical tius united Bythites, 434. 



cc. Vertical fins separate ; tail diphycercal .Dinematichthys, 435. 



hJ). Vertical fius well separated; pyloric cceca mostly numerous; tail isocercal. 

 d. Frontal bono single, normal. {Gadinw.) 



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

 barbels 3 to 5. 



/. Ventral rays 3 to 5 ; anal fin entire Onos, 436. 



ee. Anterior doisal composed of distinct rays, 

 g. Chin with a barbel. 



h. Dorsal tins two ; anal fin one. 

 i. Ventral fins narrow, filamentous, each composed of two or three 



slender rays Phycis, 437. 



it. Ventrals broader, each of about six rays. 

 j. Tail attenuate; anal fin notched ; mouth inferior; deep-sea fishes. 



Halopouphyrus, 438. 

 jj. Tail normal ; anal fin entire ; mouth terminal. 



k. Vomer toothless; teeth v ill iform Physiculus, 439. 



Ik. Vomer with teeth. 



7. Vomer and mandible with canines Molva, 440. 



II. Vomer and mandible without canines Lota, 441. 



* Including family 119, BrotuUdce, in the key to the families, page 79. 



