Artificial Key to the Families of American Food and Game Fishes 



N. Lateral line well developed. 

 O. Teeth present, no accessory branchial organ. 

 P. Mouth small, horizontal; posterior part of tongue and roof of mouth 



covered with coarse-paved teeth X, Albulid^, 88 



PP. Mouth large, the teeth all pointed, some of them canine, none paved or 



molar XI, Hiodontid^, 90 



00. Teeth none; an accessory branchial organ behind gill cavity. 



XII, Chanid^, 94 

 NN. Lateral line wanting; no gular plate. 



Q. Mouth moderate, terminal, the maxillary of about 3 pieces; stomach not 



gizzard-Hke XIII, Clupeid^, 95 



QQ. Mouth subinferior, very large, below a tapering, pig-like snout; maxillary 



very long XIV, Engraulid^, 112 



BB. Dorsal fins 2, the anterior of spines only, the posterior chiefly of soft rays. 

 R. Pectoral fin with 5 to 8 lowermost rays detached and filamentous. 



XXVIII, POLYNEMIDiE, 261 



RR. Pectoral fin entire. 



5. Teeth strong, unequal; lateral line present. . . . XXVII, Sphyr^nid^, 258 

 55. Teeth small or wanting; lateral line obsolete. 



T. Dorsal spines 4, stout; anal spines 3 XXVI, Mugilid^, 250 



TT. Dorsal spines 4 to 8, slender; anal spine single. .XXV, Atherinid^, 248 

 BBB. Dorsal fin soft-rayed, followed by a series of detached finlets. 



XXIII, SC0MBRES0CID.iE, 246 



II.— VENTRAL FINS PRESENT, THORACIC OR SUB-JUGULAR, THE 

 NUMBER OF RAYS DEFINITELY I, 5 



A. Body more or less scaly or armed with bony plates. 



B. Suborbital with a bony stay which extends across the cheek to or towards 



the preopercle; cheek sometimes entirely mailed. 



C. Slit behind fourth gill small or wanting LXVI, Scorp.«nid^, 495 



CC. Slit behind fourth gill large; body scaled. 



D. Nostril single on each side, a small pcre above it; dorsal fin continuous. 



LXVIII, Hexagrammid^, 499 



DD. Nostrils 2 on each side; dorsal fins 2 LXVII, Anoplopomid^, 498 



BB. Suborbital stay wanting; cheeks not mailed. 



E. Dorsal spines all or nearly all disconnected from each other. 



F. Body elongate, spindle-shaped XL, Rachycentrid^, 323 



FF. Body oblong or ovate, compressed XXXVIII, Carangid^, 296 



EE. Dorsal spines (if present) all, or most of them, connected by membrane. 



G. Pectoral fin with 4 to 9 lowermost rays detached and filiform. 



XXVIII, POLYNEMID^, 261 



GG. Pectoral fin entire. 

 H. Dorsal and anal each with i or more detached finlets. 



/. Anal preceded by 2 free spines XXXVIII, Carangid^, 296 



//. Anal not preceded by 2 free spines XXXII, Scombrid^, 272 



HH. Dorsal and anal without finlets. 



J. Lateral line armed posteriorly with a series of keeled plates; 2 free anal 

 spines; gill-membranes free from isthmus. 



XXXVIII, Carangid^, 296 

 JJ. Lateral line armed posteriorly with a sharp, movable, lancet-like spine, or 

 with a few bony tubercles; scales small, rough; gill membranes ad- 

 herent to isthmus LXIII, Teuthidid^, 486 



yjj. Lateral line unarmed. 



K. Throat with 2 long barbels (placed just behind chin) ; dorsal fins 2. 



XXXI, Mullid^, 268 

 KK. Throat without long barbels. 



L. Anal fin preceded by 2 free spines (these obsolete in the very old, joined 



by membrane in the very young). 

 M. Preopercle entire; teeth moderate if present. XXXVIII, Carangid.«, 296 



542 



