Cuar. X.] THE THERAPON. 337 
in their internal organisation that they differ most from 
the perches of Europe; their skeletons are composed of 
THERAPON QUADRILINEATUS, 
fewer vertebre, and the air bladder of the Therapon is 
divided into two portions, as in the carps. Four species 
at least of this genus inhabit the lakes and rivers of 
Ceylon, and one of them, of which a figure is given above, 
has been but imperfectly described in any ichthyo- 
logical work! ; it attains to the length of seven inches. 
In addition to marine eels, in which the Indian coasts 
abound, Ceylon has some true fresh-water eels, which 
never enter the sea. These are known to the natives 
under the name of Theliya, and to naturalists by that of 
Mastacembelus. They have sometimes in ichthyological 
systems been referred to the Scombride and other ma- 
rine families, from the circumstance that the dorsal fin 
anteriorly is composed of spines. But, in addition to the 
in the spinous dorsal fin. There 
are two specimens in the British 
1 Holocentrus quadrilineatus, 
Bloch. It is allied to Helotes 
polytenia, Bleek. from Halma- 
heira, from which it can be 
readily distinguished by having 
only five or six blackish longitu- 
dinal bands, the black humeral 
spot being between the first and 
second; another blackish blotch is 
Museum collection, one of which 
has recently arrived from Amoy ; 
of the other the locality is un- 
known. See Ginruer, Acanthopt. 
Fishes, vol. i. p. 282, where mention 
of the black humeral spot has been 
omitted, 
