FISHES OF THE GULF OF MAINE 13 



Key D — Continued 



4. Mouth large and strongly oblique; no ventral fins Wrymouth, p. 368 



Mouth small and horizontal; small ventral fins Rook eel, p. 359 



5. Without ventral fins Eel family key, p. 78 



Small but distinct ventral fins, situated forward of the pectorals 6 



6. Ventrals are situated behind the gill opening Eelpout family key, p. 376 



Ventrals situated on the chin, well in front of the gill openings, and reduced to forked, 



barbel-like structures Cusk eel, p. 384 



7. Ventral fins situated below point of origin of pectorals; eye very large — 



Grenadier family key, p. 467 



Ventral fins situated behind tip of pectorals; eyes very small Chimeera, p. 73 



Key E 



Bony fishes with two kinds of dorsal fins, i. e., one in front supported by rays, with a fleshy (adipose) fin behind it.' (From 



No. 14, p. 11.) 



1. Rayed dorsal fin much longer than head, and spiny Lancetfish, p. 155 



Rayed dorsal fin shorter than head, and soft-raj'ed 2 



2. Jaws armed with long projecting saber-like fangs Viperfish, p. 153 



Teeth small 3 



3. Noticeable series of phosphorescent organs along each side 4 



No phosphorescent organs 6 



4. Mouth gapes back beyond eye Lanternfish family, p. 149 



Mouth does not gape back as far as eye Pearlsides, p. 151 



6. Tail deeply forked; nose pointed Smelt family key, p. 140 



Tail nearly square or only slightly forked; nose rounded Salmon family key, p. 126 



Key F 



Bony fishes with snouts of ordinary form, symmetrical tails, bodies not entirely encased in bony plate, caudal flna distinct from 

 anal, and two or more well-developed dorsal fins, all of them supported by rays or spines (from No. 19, p. 12) . 



1. All fins soft rayed; no spines Cod and silver hake families key, p. 385 



First dorsal fin spiny; second soft-rayed 2 



2. One or more small finlets between second dorsal and anal fins and the caudal 3 



No such finlets 4 



3. More than 3 each dorsal and anal finlets Mackerel family, p. 188 



Two dorsal and two anal finlets Escolar, p. 220 



Only one dorsal and one anal finlet Mackerel scad (pompano family in part), p. 232 



4. Sides of head bony, with sharp spines or horns; head very broad 5 



Sides of head have no spines or horns ; head not noticeably broad 6 



5. Three lower rays of each pectoral fin separate from others, in the form of fleshy 



feelers; outline of tip of snout, as seen from above, concave; mouth small 



Sea robin family key, p. 345 



Lower rays of pectorals not separate from others; outline of tip of snout convex, 

 not concave; mouth very large Sculpin family key, p. 314 



6. First spine of first dorsal fin very much stouter than others and can be locked erect by 



the second; no ventrals; skin very hard Triggerfish, p. 293 



First dorsal spine not stouter than others; ventral fins well developed; skin soft 7 



7. Ventrals more than twice as long as pectorals; caudal very small John Dory, p. 291 



Ventrals no longer than pectorals; caudal fin large 8 



8. Space between two dorsal fins is as long as the first dorsal; ventrals are situated be- 



• hind the middle of the pectorals 9 



Little or no free space between the two dorsal fins; ventrals in front of middle of 

 pectorals 10 



' The tileflsh (pp. 11 and 352) has a fleshy flap, simulating an adipose fln, on the back in front of the rayed dorsal fin. 



