FLYING FISHES AND THEIR HABITS. 497 



I. TUK P]X()((KT()I1) FlYINC; FlHIIlOS. 



I. 



The Exococtids, or true flying-fish family, manifest considerable 

 diversity in form and in extension of the jaws, but agree in having the 

 siipramaxillaries only in contact (and not united) with the intermaxil- 

 laries, lower pharyngeals united in a broad triangular body, third 

 pair of upper pharyngeals much enlarged, and the vertebrae desti- 

 tute of zygapophysoid processes. They naturally fall into three 

 groups or subfamilies, the Flying fishes proper or Exoccetines, the 

 Sauries or Scomberesocines, and the Ilalfbeaks or Hemirhamphines. 



Another very characteristic feature is the course of the lateral line; 

 this is developed low down on each side of the abdomen and above 

 the anal fin to the lower lobe of the caudal. 



The flying fishes proper, or Exocoetines, have both jaws rounded or 

 simply angulated in front, and the pectoral fins are generally greatly 

 enlarged and adaj^ted to the sustentation of the body in the air. Not- 

 Avithstanding this striking specialization of the group, there are con- 

 siderable differences. All agree, however, but in various degrees, in 

 provision for emergence by leaping from the water and for progress 

 in the air. 



The form is adapted for the life most of them lead; the subfusi- 

 form shape, with a quadrate periphery and with the sharp cut front, 

 is fitted for progress in water as well as air Avith the least friction. 

 The elongated lower lobe of the caudal enables a final strong u})ward 

 impulse to be given to the leaping fish ; the pectoral and ventral fins 

 are enlarged with the maximum of surface to sustain the body in the 

 air and the minimum of weight in the framework. Their foremost 

 rays are also sharp edged forward so as to act, in analogy with cut- 

 waters, as " cutairs " as well as cutwaters. The air bladder is greatly 

 enlarged and filled with a gaseous emanation (mostly nitrogen), 

 which diminishes the relative weight of the body. 



The flying fishes are mostly true pelagic animals, and some — one or 

 more — may be met with in midocean in every tropical and sub- 

 tropical sea, while a few wander into northern and southern tem- 

 perate regions. Although such ma}^ be the case, however, most of 

 them probably live within 100 or 200 miles of land, and the geo- 

 graphical distribution of some, at least, is not much less restricted 

 than that of ordinary shore fishes. "About 65 species " have been 

 described, and of those about 20 have been found in American seas, 

 the others, of course, being limited to that extent at least. Five of 

 the American species have not been found elsewhere, Cypselurus 

 xenoyterus^ C. calif ornicus^ and C. callo'pterus being known only from 

 SM 1904 32 



