PISHES. 209 



** First dorsal with 4 stiff spines ; body compressed ; a6 lateral 

 band Mugilidm, the Mullets. 



FAMILIES OF HEMIBRANCHII. 



* Bones of head moderately produced ; ventral flns of a stout 



spine and a rudimentary ray; dorsal preceded by free spines; 

 scaleless, naked or with bony plates; an oblong, silvery, 

 naked area in front of pectorals. . G-ASTBKOSTEiDja;, 98. 

 ** Bones of head much produced, forming a long tube which 

 bears the short jaws at the end; ventral flns without spine, 

 f Body compressed; no teeth; scales small; dorsal flns two; 

 first with spines. . . Centriscidce, the Snipe Fishes. 

 •ff Body greatly elongated ; teeth present; no scales; no dorsal 

 spines; middle rays of caudal produced into a long fila- 

 ment. . . . Fistulariidce, the Trumpet Fishes. 



FAMILIES OF SYNENTOGNATHI. 



* Jaws one or both elongated into a long beak, 

 f Both jaws elongated; no flnlets; size large. 



Belonidm, the Ga/r-Fishes. 

 ff Lower jaw only elongate, or else dorsal and anal with 

 detached finlets, as in the Mackerels. 



8combereaocid(B, the Bcmries. 



** Jaws moderate ; pectorals elongated, nearly as long as body, 

 used for " flying." . . Exocatidce, the Flying Fishes. 



FAMILIES OF HAPLOMI. 



* Snout depressed and elongated, its length more than half the 



greatest depth of body ; jaws, vomer, palate and tongue armed 

 with strong, hooked teeth ; body elongated, sub-terete ; size 

 large ; in fresh water EsooiD.a;, 103. 



** Snout rounded and rather short, its length being less than half 

 the greatest depth of body; teeth moderate; size small. 



f Vent jugular, in front of pectorals ; eyes often undeveloped ; 

 ventrals small or wanting; cave fishes. AmbIjTOPsid^, 103. 



ft Vent normal : eyes present ; ventrals well developed. 

 14 



