164 FISHES OF NORTH CAROLINA. 



chiefly by the premaxillaries, which are not joined to the maxillaries; jaw teeth 

 small and weak; eye large; nostrils large, double, and close to eye; gill-mem- 

 branes not connected, and free from isthmus; pseudobranchise glandular; air- 

 bladder large and extending far backward; scales rather large, cycloid, covering 

 entire body and most of head; lateral line on level with ventral fins; dorsal fin 

 placed posteriorly, relatively small, and containing only soft rays; anal opposite 

 and similar to dorsal, but smaller; caudal deeply forked, the lower lobe much the 

 longer; ventrals abdominal, usually large and placed posteriorly. 



The "flight" of the flying-flshes has been much discussed. Many people 

 have contended that the greatly enlarged pectoral fins are veritable wings and are 

 used as birds' wings are, while others have held that the propelling force is in the 

 tail and that the pectorals are incapable of rapid and active flapping. With 

 regard to this question it may be stated that the shape and structure of the pec- 

 torals, the nature of their insertion, and the position and character of their mus- 

 cular attachments prevent the use of these fins in the air except as sailing or 

 balancing organs. The flight of Cypselurus californicus, the largest and most 

 powerful of the family, has been studied under particularly favorable circum- 

 stances, and is thus described by Jordan and Evermann (1896, p. 730) : 



The flying-fishes live in the open sea, swimming in large schools. They will "fly" a dis- 

 tance of from a few rods to more than an eighth of a mUe, rarely rising more than 3 or 4 feet 

 Their movements in the water are extremely rapid; the sole source of motive power is the 

 action of the strong tail while in the water. No force is acquired whUe the fish is in the air. 

 On rising from the water, the movements of the tail are continued until the whole body is out 

 of the water. While the tail is in motion, the pectorals seem to be in a state of rapid vibration, 

 but this is apparent only, due to the resistance of the air to the motions of the animal. While 

 the tail is in the water, the ventrals are folded. When the action of the tail ceases, the pect- 

 orals and ventrals are spread and held at rest. They are not used as wings, but act rather 

 as parachutes to hold the body in the air. When the fish begins to fall, the tail touches the 

 water, when its motion again begiQS, and with it the apparent motion of the pectorals. It is 

 thus enabled to resume its flight, which it finishes finally witli a, splash. While in the air it 

 resembles a large dragon-fly. The motion is very swift, at first in a straight line, but later 

 deflected into a curve. The motion has no relation to the direction of the wind. When a 

 vessel is passing through a school of these fishes, they spring up before it, moving in all direc- 

 tions, as grasshoppers in a meadow. 



In addition to the species actually known from the coast of North Carolina, 

 various others undoubtedly occur and will in time be detected. The genera 

 represented by these species are thus differentiated: 



i. Pectoral fins of moderate length, not extending beyond middle of dorsal fin; dorsal fin very 



high; body elliptical in cross section Parexoccetus. 



ii. Pectoral fins very long, extending beyond base of dorsal and in some species to base of 

 caudal; dorsal fin low; body angular in cross section. 

 a. Ventral fins small and inserted nearer tip of snout than base of caudal, their ends not ex- 

 tending as far as dorsal Exoccetus. 



aa. Ventral fins large and inserted nearer base of caudal than end of snout, their ends reaching 

 beyond origin of dorsal Ctpselukus. 



