ARTIFICIAL KEY. 29 



SERIES II. VENTRAL FINS PRESENT, THORACIC OR JUGULAR. 

 A. Eyes unsymmetrical, both on same side of head. . PLEURONECTID^E, 89. 

 A A. Eyes symmetrical. 

 B. Gill openings in front of pectorals. 



C. Body more or less scaly, or armed with bony plates. 

 D. Ventral fins united into one; no lateral line; gill membranes 



joined to isthmus. GOBHD.E, 82. 



DD. Ventral fins separate. 

 E. Top of head with a large sucking-disk, modified from the spinous 



dorsal ECHENEIDID.E, 50. 



EE. Top of head without sucking-disk. 

 F. Ventral rays, I, 5. 



G. Suborbital with a bony stay which extends across the cheeks 

 to or towards the preopercle; cheeks sometimes entirely 

 bony. 



H. Pectoral fin with 2 or 3 lower rays detached and separate. 



TKIGLID.E, 76. 

 HE. Pectoral fin entire; slit behind fourth gill small, or 



wanting. 

 /. Dorsal spines, 9 to 17 ; anal spines three ; eyes lateral. 



SCORP-SNID^E, 72. 



II. Dorsal spines, four; eyes superior. URANOSCOPID^E, 81. 

 GG. Suborbital stay wanting; cheeks not mailed. 

 K. Dorsal spines all or nearly all unconnected by membrane. 



L. Body elongate, subterete ELACATID^E, 51. 



LL. Body oblong or ovate, compressed. 

 M. Caudal peduncle very slender, the fin widely forked. 



CARANGID^E, 56. 

 M M. Caudal peduncle stout, the fin little forked. 



STROMATEIDJE, 58. 



KK. Dorsal spines, if present, mostly connected by membrane. 

 N. Dorsal and anal each with 4 or more finlets; scales minute. 



SCOMBRID^E, 55. 



NN. Dorsal and anal without finlets, or with but one each. 

 0. Throat with two long barbels .... MULLID^E, 67. 

 00. Throat without barbels. 

 P. Anal preceded by two free spines (these often obsolete 



with age). 



Q. Scales very small, cycloid. . . CARANGID^E, 56. 

 QQ. Scales moderate, ctenoid. . . POMATOMID^E, 57. 

 PP. Anal without free spines. 



R. Tail with a fleshy keel on each side. 



CARANGID^S, 56. 

 RR. Tail not keeled. 



S. Dorsal fin very long, without distinct spines; 



caudal deeply forked. . CORYPH^ENID^:, 59. 



SS. Dorsal fin with distinct spines; gill membranes 



free from isthmus. 

 T. Vomer with teeth. 



U. Anal spines none ; eyes on top of head. 



URANOSCOPID^, 81. 

 U U. Anal spines, one or two. 



