ADDITIONAL NOTES ON FLYING-FISH. 



207 



straight shot. With a little practice, however, it is quite easy 

 to bring the binocular to bear as the fish leaves the water. 



If you handle a fresh specimen and open the closed wings 

 you will find that they spread in the same plane as that in 

 which the body lies. Col. Durnford likens the action of the 

 opening and shutting to that of a fan, which is very nearly 

 correct ; by the way, it is difficult to see from a mechanical 

 point of view how a purely horizontal, fan-like motion can propel 

 the fish at all. I think the following attempt to describe the 

 flight in detail will furnish the explanation that the action is 

 neither quite horizontal nor quite fan-like ; besides which the 

 constant vibration of the tail must not be forgotten. 



The line of the insertion of the wing is down the side of the 

 body, and is almost perpendicular to the plane of the outspread 

 wings ; the uppermost ray of the closed wing becoming the 

 foremost ray of the wing extended, the lowest ray of the closed 

 wing keeping its position down to the body. The operation 

 is difficult to describe clearly, but by actually opening and 

 shutting the wings of a specimen rapidly it becomes evident 

 that a certain amount of air must be caught in the closing and 

 none in the opening, the wings acting like an oar " feathering," 

 or like the hands of a swimmer who drives the water past him 

 with his concave palms. However, the almost fan-like and 

 horizontal action of the wings does not appeal to one as an 

 ideal method of propulsion, and one cannot wonder that a high 

 rate of wing vibration added to that of the tail is necessary to 

 propel such a solidly built object as a Flying-Fish. 



When about a hundred miles south-east of Pernambuco a rare 

 specimen came on board, which I was lucky enough to secure, 

 and which Mr. G. A. Boulenger was kind enough to identify for 

 me as Exocoetus furcatus. Its peculiarity lay in the possession of 

 two barbel-like appendages in. in length. I had never pre- 

 viously seen a specimen, nor had any of the sailors of whom I 

 inquired, and the " Flying-Fish with whiskers" was much dis- 

 cussed in certain rendezvous of skippers in Montevideo and other 

 ports of the Plate. 



