7S Tail Region — True Fishes 



I. Keels on each side of the body near the tail, on the 

 caudal peduncle 

 Page 79, figs. A-F 



la. No median keel; two keels, one above and the 

 other below the center of the caudal peduncle; tail 

 forked 

 Page 79, figs. A-C 



See Mackerels, p. 126. 



lb. Median keel present; two other keels also present, 

 one above and the other below the center of the 

 caudal peduncle; tail crescent-shaped 

 Page 79, figs. D-F 



See Frigate Mackerel, Bonito, Tunas, Spanish 

 Mackerel, p. 118. 



II. No keels on each side of the body near the tail, on the 

 caudal peduncle 

 Page 79, figs. G, H 



See Leatherjacket, p. 363. 



