662 



feet, and excellent eating, 

 fresh waters. 



FISHES. 



Young specimens enter freely 



Chanos. — Body oblong, compressed ; abdomen flat. Scales 

 small, striated, adherent ; lateral line distinct. Snout depressed ; 

 mouth small, anterior, transverse, the lower jaw with a small 

 symphysial tubercle. Intermaxillary in juxtaposition to the 

 upper anterior edge of maxillary. Teeth none. Dorsal fin 

 opposite to the ventrals ; anal small, shorter than dorsal ; caudal 

 deeply forked. Gill-membranes entirely united below, and free 

 from the isthmus. Branchiostegals four, long. An accessory 

 branchial organ in a cavity behind the gill-cavity proper. Air- 

 bladder divided by a constriction into an anterior and posterior 

 portion. Mucous membrane of the oesophagus raised in a spiral 

 fold. Intestine with many convolutions. 



Two species from the ludo-Pacific, of which Ch. salmoneus 

 is extremely common ; it enters fresh waters, and exceeds a 

 length of four feet ; its flesh is highly esteemed. The acces- 



Fig. 302. — Chanos salmoneus. 



sory branchial organ and the skeleton have been described by 

 Muller, "Bau und Grenzen der Ganoideu," p. 75 ; and by Hyrtl, 

 " Denkschr. Ak. Wiss. Wien." xxi. 1883, p. 1. 



The remaining genera belonging to this family are S2yra- 

 telloides, Dussumicria, and Mrunieus, which together form a 

 small group, distinguished by an anterior and lateral mouth, 

 by the upper jaw not overlapping the lower, by a rounded 

 abdomen, and by lacldug the gular plate of some of the pre- 

 ceding genera. 



