PISHES. 



143 



food-fish. The three species of Osteoglossum are remarkably distributed, one being 

 found in Brazil, one in Australia, and the third in the East Indies. The single species 

 of Heterotis inhabits the Nile. 



The Galaxiid^ are small fishes, somewhat trout-like in appearance, found in New 

 Zealand, Australia, and the southern parts of South America. The body is rather elon- 

 gate, and without scales. The dorsal fin is opposite the anal, and similar to it, and 

 there is no adipose fin. As in the Salmonidse, there is no oviduct, the eggs falling 

 into the cavity of the abdomen before exclusion. About twelve species are recorded, 

 nearly half of them from New Zealand, where these fishes are most abundant, and 

 where they are locally known as trout. 



Fig. Wi,—Arapaima gigas. 



The HAPLOCHiTOinD^ are still more trout-like, differing from the Salmonidse 

 chiefiy in the structure of the mouth, the entire margin of the upper jaw being formed 

 by the j)remaxillary. Four species are known, belonging to the genera Haplochiton 

 and Prototroctes. The former is naked, and inhabits the lakes of Tierra del Puego and 

 the Falkland Islands. The latter is found in Australia and New Zealand, where it is 

 often called grayling. In Prototroctes, the body is scaly. 



The small family of Salangidje comprises two species allied to the Argentinidse, 

 but with the alimentary canal straight for its whole length and without pyloric appen- 



