572 FISHES. 



Glyptosternum, a genus represented by eight species in moun- 

 tain streams of the East Indies, and differing from the Syrian 

 species in lacking the teeth on the palate. 



V. SiLUEiD^ STENOBRANCHiiE. — The rayed dorsal fin is 

 short, if present, helonging to the ahdominal portion of the verte- 

 hral column, the ventrals heincf inserted hehind it (except in 

 Rhinoglanis). The gill-memlranes are confluent with the skin 

 of the isthmus. 



a. DOEADINA. 



Some of the genera have no bony shields along the lateral 

 line, and a small adipose fin or none whatever ; all of these 

 are South American — Ageniosus, Tetranematichthys, Uuane- 

 m,us,Auchenipterus, Glanidium, Centromochlus, Trachelyopterus, 

 Cetopsis, and Astr'ophysus. 



Others have a series of bony scutes along the middle of 

 the side ; they form the genus Boras with two closely allied 

 forms, Oxydoras and Rhinodoras. Some twenty-five species 

 are known, all from rivers of tropical America, flowing into 

 the Atlantic. These fishes have excited attention by their 

 habit of travelling, during the dry season, from a piece of water 

 about to dry up, in quest of a pond of greater capacity. 

 These journeys are occasionally of such a length that the 

 fish spends whole nights on the way, and the bands of 

 scaly travellers are sometimes so large that the Indians who 

 happen to meet them, fill many baskets' of the prey thus 

 placed in their hands. The Indians supposed that the fish 

 carry a supply of water with them, but they have no special 

 organs, and can only do so by closing the giR-openings, or by 

 retaining a little water between the plates of their bodies, as 

 Hancock supposes. The same naturalist adds that they make 

 regular nests, in which they cover up their eggs with care 

 and defend them, male and female uniting in this parental 

 duty untn the eggs are hatched. The nest is constructed at 



