2852 



THE BONY FISHES AND GANOIDS 



upper jaw is formed both by the premaxillae and maxillse, the gill openings are 

 wide, and false gills are wanting. The long dorsal closely resembles the anal fin, 

 over which it is placed in the caudal region of the body; both coming very close to 

 the tail fin, with which they may unite as an abnormality. In structure the air 

 bladder may be either simple or divided into cells. 



Arapaima 



BRAZILIAN ARAPAIMA. 



(One-twentieth natural size.) 



The true arapaima (Arapaima gigas) of the larger rivers of 

 Brazil and the Guianas, which is the sole representative of its genus, 

 occupies the proud position of being the largest fresh- water bony fish, its length 

 not unfrequently exceeding fifteen feet, while its weight may reach upward of four 

 hundred pounds. As a genus, it is distinguished by the broad cleft of the mouth, 

 in which the lower jaw is very prominent, and the absence of barbels, as well as by 

 the rounded lower surface of the body, and the moderate length of the pectoral 

 fins. In addition to an outer series of small conical teeth in the margins of the 

 jaws, there are rows of rasp-like teeth not only on all the bones of the palate, 

 but likewise on the tongue and hyoid bones. In spite of its enormous dimensions, 



