508 FLYING FISHES AND THEIR HABITS. 



beyond the first rays of anal; fnrther, the ventrals are acutely elon- 

 gated at the third ray and the first two short and compressed. The 

 species so distinguished are combined in the genus Cypselurus. 



A few species agreeing in most respects with the Cypsehirl differ in 

 the insertion of the ventral fins in advance of the middle of the body 

 as well as in their brevity; the fins are also truncate or emarginate 

 and very short, not extending to the anus; the pectorals are moder- 

 ately elongate. They constitute the genus Exocoetus and the only 

 species of the entire group {E. r oh' tans) known to Linnaeus is one. 



A few other species agreeing fundamentally with the Exocceti have 

 the ventrals submedian and rather short but angulated by the exten- 

 sion of the third ray; the pectorals are moderately long; further- 

 more, the roof of the mouth is more dentigerous, the vomer, palatines, 

 and pterygoids being armed with teeth. These have been set apart 

 in a genus called ParexoccBtus, the type of which is the P. mento of 

 the Indian and Sunda-Moluccan seas. An American species is the 

 T. hillianus of the Caribbean Sea. 



One species is separated from all others by the pike-like head, the 

 snout being longer than the postorbital region and the lower jaw 

 elongated, projecting in front and with a flat, triangular area; the 

 pectorals are moderately elongated, the ventrals rather short and 

 rounded behind. The single species is the Fodiator acutus of the 

 tropical American seas. 



The differences thus indicated are coincident with others. 



II. The Dactylopterids, or Flying Gurnards. 



I. 



The Dactylopterids, otherwise known as Flying Gurnards or Fly- 

 ing Gurnets, differ radically and in innumerable characters from the 

 true Gurnards, and vastly more from the Exocoetoid flying fishes, but 

 a few external ones Avill suffice to give an idea of the family. The 

 elongated body is somewhat swollen upward under the first dorsal, 

 and covered with hard-keeled scales ; the head is oblong and parallel- 

 opiped, and the suprascapular bones form an integral part of the 

 skull, and extend far back as flat spiniform processes on each side of 

 the dorsal fin; the preoperculum of each side is armed at its angle 

 with a long horizontal spine reaching backward under the pectoral; 

 the jaws have granular teeth; the branchial apertures are con- 

 tracted ; the dorsal fins short, as is also the anal ; the pectorals divided 

 into tv,'o parts, a small anterior and a very large posterior, which 

 spread out sideways; the ventrals imperfect and not far apart. The 

 pectorals are set upon osseous bases (actinosts) differentiated for the-. 

 two parts. 



