654 FISHES. 



mosaic. Head scaleless ; its integuments marly entirely replaced 

 hy hone ; lateral line composed of wide openings of the mucus- 

 dud. Margin of the upper jaw formed hy the intermaxillaries 

 mesially, and hy the maxillaries laterally. The dorsal fin 

 belongs to the caudal portion of the vertebral column, is opposite 

 and very similar to the anal fin ; hoth approximate to the 

 rounded caudal (with which they are abnormally confluent). 

 Gill-openings wide ; fseudobranchioe none ; air-hladder simple 

 or cellular. Stomach without coecal sac ; pyloric appendages 

 two. 



Large freshwater-fishes of the tropics, whose siagular 

 geographical distribution has been noticed above (p. 223). 



OsTEOGLOSSim. — Cleft of the mouth very wide, oblique, with 

 the lower jaw prominent. A pair of barbels at the lower jaw. 

 Abdomen trenchant. Bands of rasp-like teeth on the vomer, 

 palatine and pterygoid bones, on the tongue and hyoid. Pectoral 

 fins elongate. 



0. hicirrhosum from Brazil and Guyana, 0. formosum from 

 Borneo and Sumatra, 0. leichardti from Queensland. 



Arapaima. — Cleft of the mouth wide, with the lower jaw 

 prominent; barbels none. Abdomen rounded. Jaws with an 

 outer series of small conical teeth ; broad bands of rasp-like teeth 

 on the vomer, palatines, pterygoids, sphenoid, os linguale, and 

 hyoid. Pectoral fins of moderate length. 



Fig. 299. — Arajlaima gigas. 



The largest freshwater Teleostean known, exceeding a 

 length of 15 feet and a weight of 400 pounds. It is common 

 in the large rivers of Brazil and the Guyanas, and esteemed as 

 an article of food. When salted it is exported in large 

 quantities from the inland fisheries to the seaports. 



