8 FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Key E — Continued 



15. First dorsal fin soft-rayed; second dorsal fin at least 5 times as long as first dorsal. 



refer to Cod family key, in part, p. 173 

 First dorsal fin noticeably spiny; second dorsal fin as long as first dorsal 16 



16. Second dorsal fin not much longer than the anal fin refer to Sea bass family key, in part, p. 389 



Second dorsal fin is about twice as long as the anal fin refer to Weakfish family key, p. 417 



Key F 



Bony fishes with snouts of ordinary form; symmetrical tails; caudal fin distinct from the anal fin; neither with bar- 

 bels on the top of the snout nor with canine tusks; and with only one well-developed dorsal fin; the latter is soft- 

 rayed except that it may be preceded by a few short spines or by a series of hair-like rays without connecting 

 membrane and that there may be an isolated spine on the top of the head (from No. 26, p. 6). 



1. The rear parts of the dorsal fin and of the anal fin are broken up into series of almost separate finlets (fig. 191) 2 



The rear parts of the dorsal and anal fins are not broken up into series of finlets 3 



2. The forward parts of the dorsal and anal fins are very high and scythe-shaped; the pectorals are very long, reaching 



back considerably beyond the high part of the dorsal fin; there are no spines in front of the anal fin. .Sea bream, p. 361 

 The dorsal and anal fins are not very high and slope gradually rearward; the pectorals are small, their tips falling 

 far short of the level of the front of the dorsal fin; the anal fin is preceded by two short stout spines. 



Leather jacket, p. 380 



3. The mouth gapes back far beyond the eye refer to Anchovies key, p. 118 



The mouth does not gape back much beyond the rear edges of the eyes, if that far 4 



4. The whole of the anal fin is behind the rear end of the dorsal fin refer to Herring Tribe key, p. 85 



Part or all of the anal fin is further forward than the rear end of the dorsal fin 5 



5. There is a spine or a bristle-like rod on the top of the head over the eyes 6 



There is no spine or bristle-like rod on the head over the eyes, but there may be a few short spines close in front of 



the dorsal fin 7 



6. The spine on the top of the head is thick and very stiff and has no fleshy tab at its tip; mouth small; body stiff; fin 



rays slender, not fleshy refer to Filefish family, key, p. 521 



The spine on the head is slender and flexible and has a fleshy tab or "bait" at its tip; body soft; mouth very large; 

 fin rays thick and fleshy Deep-sea angler, p. 543 



7. Form eel-like; snout sharp pointed Launce, p. 488 



Form not eel-like; snout blunt 8 



8. Dorsal fin originates on the head, about over the eyes Dolphin, p. 360 



Dorsal fin originates far behind the eyes 9 



9. Each ventral fin is represented by a single large stout spine refer to Stickleback key, p. 307 



The ventral fins are of ordinary rayed type, or are lacking 10 



10. The upper anterior profile of the head is conspicuously concave 11 



The upper anterior profile of the head is more or less convex __12 



11. The forward parts of the dorsal fin and of the anal fin are much higher than the rear parts, the first few rays of each 



being very much longer than the rays farther back Lookdown, p. 379 



The dorsal and anal fins are only a little higher in front than rearward, the first few rays not being much longer than the 

 rays farther to the rear Moonfish, p. 378 



12. The forward rays of the dorsal and anal fins are very long and thread-like Thread-fin, p. 381 



The forward rays of the dorsal and anal fins are not very long and thread-like 13 



13. The entire body is armored with several rows of overlapping plates Alligator fish, p. 457 



The body is not armored with overlapping plates 14 



14. The skin is rough or prickly Refer to Puffers and Porcupine fishes, key, p. 526 



The skin is smooth, though scaly 15 



15. The front part of the dorsal fin is much higher than the rear part 16 



The front part of the dorsal fin is not much higher than the rear part 17 



16. The ventral fins are large and conspicuous Opah, p. 247 



There are no ventral fins Refer to Butterfish and Harvest Fish, key, p. 363 



17. The tail fin is conspicuously rounded 18 



The tail fin is more or less deeply forked 19 



18. The dorsal fin runs the whole length of the back from close behind the head to the caudal fin which it joins; there 



is a barbel on the chin Cusk, p. 238 



The dorsal fin occupies only about one-third of the length of the back or less, and stands far to the rear; there is a 

 considerable space between it and the caudal fin; there is no barbel on the chin. .Refer to Mummichog key, p. 162 



