662 FISHES. 



feet, and excellent eating. Young specimens enter freely 

 fresh waters. 



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 Indo-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- 



Pig. 302. — Chanoa salmoneus. 



sory branchial organ and the skeleton have been described by 

 Muller, "Ban und Grenzen der Ganoiden," p. 75 ; and by Eyrtl, 

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



The remaining genera belonging to this family are Spra- 

 telloides, Dussumieria, and Mrumeus, 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 lacldng the gular plate of some of the pre- 

 ceding genera. 



