ii6 



I. Fam. Belonidae. 



Very elongate, slender, cylindrical or compressed. Mouth 

 very large. Jaws produced and narrowed forwards, forming a 

 slender beak. Maxillaries more or less concealed below the 

 large praeorbital. Both jaws with bands of small, teeth and 

 with a single series of distant canines. Teeth on vomer and 

 tongue present or absent. Pectorals inserted rather high, of 

 moderate length. Dorsal far back, beginning above or behind 

 anal, both fins rather long without detached rays forming 

 finlets. Caudal forked, emarginate, truncate or rounded. Scales 

 cycloid, small or very small, present on praeoperculum, but 

 sometimes absent on operculum. Lateral line running low down, 

 more or less elevated and sometimes forming a keel on the 

 caudal peduncle. Gillopenings wide, gillmembranes not united 

 with isthmus. Third upper pharyngeals moderately enlarged, 

 separate. Second and fourth pair present or absent. 



Distribution: All temperate and tropical seas. Some 

 species entering fresh water. 



Key to the indo-australian genera of Belonidae. 



I. Gillrakeis present. In indo-australian species caudal pe- 

 duncle strongly depressed, keeled Bclonc p. Ii6. 



II. Gillraicers absent or vestigial. Caudal peduncle com- 

 pressed or slightly depressed. 



A. Two or three pairs of dentigerous upper pharyngeals. 

 Operculum scaly, or if not so, the tail is forked. 

 Origin of dorsal more or less behind that of anal. 



1. Body scarcely or moderately compressed, the heigiit 

 less than twice the breadth of the body. Inter- 



maxillarics not swollen at the base Tylosiinis p. 119. 



2. Body strongly compressed. The height twice the 

 breadth of the body. Intermaxillaries swollen at 



the base. Atlilcnncs p. 130. 



/)'. Only one pair of dentigerous upper pharyngeals. 

 Caudal subtruncate or slightly rounded. Operculum 

 not scaly. Origin of dorsal opposite to that of anal. Xaicnfodon p. 132. 



I. Belone Cuvier. 



(CuviER, Rcgne animal II. 1817, p. 185). 

 Very elongate, compressed or cylindrical, caudal peduncle 

 sometimes even depressed. Intermaxillaries and mandibles 



