12 BULLETIN OP THE BUREAU OF FISHERIES 



Key A — Continued 



18. Fishes which lie flat on one side, with both eyes on the other side, the upper side 



dark, the lower pale Flatfish tribe key, p. 472 



Not lying flat on one side 19 



19. Only one well-developed dorsal fin (this, however, may be preceded by isolated spines 



or rays) 20 



Two or more separate and well-developed dorsal fins Key F, p. 13 



20. Top of snout with several barbels or beards Rocklings (cod family in part) key, p. 385 



No barbels or beard on top of snout 21 



21. Jaws with very large canine tusks which project even when the mouth is closed 



Wolffish family key, p. 370 



No large canine tusks 22 



22. Dorsal fin soft-rayed, except that there may be a short spine at its forward margin 



Key G, p. 14 



At least forward one-third of dorsal fin, if not whole length, spiny Key H, p. 15 



Key B 



Fishes with tubular snouts (from No. 3, p. 11). 



1. Head horselike; trunk deep, narrowing abruptly to slender, prehensile tail; no caudal 



fin Seahorse, p. 177 



Head roughly cylindrical; body very slender with no distinction into trunk and tail 

 portions; caudal fin present 2 



2. Snout no longer than dorsal fin; no ventral fin; caudal fin rounded Pipefish, p. 175 



Snout more than six times as long as dorsal fin; ventral fins present; caudal fin 



forked Trumpetfish, p. 173 



Key C 



Fishes with bills or swords (from No. 4, p. 11). 



1. Both jaws elongated 4 



Only one jaw elongated 2 



2. Upper jaw elongated as a sword 3 



Lower jaw elongated Halfbeak, p. 163 



3. Sword sharp-edged; first dorsal fin shorter than the sword forward of eye; no ventral 



fins . Swordfish, p. 221 



Sword round-edged; dorsal fin nearly twice as long as sword Spearfish, 6 p. 227 



4. Caudal fin well developed 5 



No caudal fin ; tip of tail is whiplike Snipe eel, p. 88 



5. Several finlets behind dorsal and anal fins Needlefish, p. 164 



No finlets behind dorsal and anal fins Silver gar, p. 161 



Key D 



Fishes with well-developed fins, snouts of ordinary form, only one gill opening on each side, and the anal fin continuous with 

 the caudal around the tip of the tail (from No. 13, p. 11.) 



1. Only one dorsal fin 2 



Two separate dorsal fins, the first much higher than the second but shorter 6 



2. Body band-shaped, the tail tapering to a whiplike tip Cutlasfish, p. 220 



Body thick, eel-like; vertical fins continue around tip of tail in a broad band 3 



3. Dorsal fin spiny from end to end 4 



Dorsal fin soft rayed, at least for almost all its length 5 



1 The sailfish would also come under this heading should one ever be taken in the Gulf of Maine. The distinctions between 

 it and the spearfish are given under the account of the latter on page 228. 



