67 



Dorsal : 



Distance from snout 56 



Length of base ..-. 13 



Greatest height 13 



Anal: 



Distance from snout 56 



Greatest height „ 14 



Caudal : 



Length of upper rays 15 



Length of lower rays 23 



Pectoral : 



Distance from snout at upper axilla .16 



Length 58 



Distance of tip from snout 80 



Ventral : 



Distance of base from snout 45 



Length 32 



Distance of tip from snout -. 78 



The JSxocoetus exiliens of Bloch is totally diflferent. 



I observed numerous specimens of the pelagic species in the vicinity 

 of the islands, both on going and return. I take from my note-book 

 some observations on their flight. 



" February 10, 1871. — Several flying-fishes were observed on approach- 

 ing the islands ; usually they were single, but often a school of half a 

 dozen or more started out from under the side of the brig. The dis- 

 tance of flight varied from six to one hundred yards. When they 

 leave the water, the pectorals assume a rapid vibration, reminding one 

 of the flight of a grouse, the tail also rapidly vibrating. The fins soon 

 assume a rigid position, and the fish rises over the crests and falls in 

 the trough of the waves, following their motion; sometimes it dashes 

 through the crest, and on re-appearing the fins are again in motion. 

 They seem unable to fly except in a straight line (I afterwards saw 

 them veering considerably from a straight line, taking a direction nearly 

 at right angles with their first course), but are not dependent on the 

 direction of the wind. The motion is very bird-like, but the illusion is 

 dispelled by the decidedly piscine splash with which the fish plunges 

 into the water. It was a truly beautiful sight as the fishes emerged from 

 the waves, their silvery fins quivering and glistening in the light." 



I am convinced that at the moment the fish leaves the water the 

 mode of propulsion changes from a true swimming motion to a true 

 flying motion. The leap with which it leaves the water is due to the 

 former, and is analogous to the spring from the ground or from a perch, 

 made by some birds in the act of taking wing. 



