622 FISHES. 



part of tlie ocean ; thus, the species figured, E. callop- 

 terus, has been hitherto found on the Pacific side of the 

 isthmus of Panama only. Their usual length is about 10 or 

 12 inches, but specimens of 18 inches have been caught. 

 They always live in shoals, and their numbers at certain 

 times and localities are immense ; thus, at Barbadoes many 

 boats engage in their capture, as they are excellent eating. 

 The pectorals are ia the various species of unequal length; 

 in some they extend to the anal fin only; in others (and 

 these are the best fliers) to the caudal. A few have ciTrious, 

 barbel-like appendages at the lower jaw, which may disappear 

 with age or be persistent throughout life. The literature on 

 the subject of Plying-fishes is very extensive, and great diver- 

 sity of opinion exists among observers as regards the mode 

 and power of their flight ; but the most reliable agree that 

 the fishes do not leave the water for the purpose of catching 

 insects (!), and that they' are unable to move their fins in the 

 manner of a bat or bird, or to change voluntarily the direc- 

 tion of their flight, or to fly beyond a very limited distance. 

 The most recent enquiries are those of K. Mobius ("Die 

 Bewegungen der Pliegenden Fische durch die Luft," Leip. 

 1878, 8vo), the chief results of which may be summed up 

 thus : Plying-fish are more frequently observed in rough 

 weather and in a disturbed sea than during calm ; they dart 

 out of the water when pursued by their enemies, or frightened 

 by an approaching vessel, but frequently also without any 

 apparent cause, as is also observed in many other fishes; 

 and they rise without regard to the direction of the wind or 

 waves. The fins are kept quietly distended, without any 

 motion, except an occasional vibration caused by the air 

 whenever the surface of the wing is parallel with the cur- 

 rent of the wind. Their flight is rapid, but gradually de- 

 creasing in velocity, greatly exceeding that of a ship going 

 10 miles an hour, and a distance of 500 feet. Generally, it 



