[Footnote 1:  In extenuation of the little that is known of the fresh-water fishes of Ceylon, it may be observed that very few of them are used at table by Europeans, and there is therefore no stimulus on the part of the natives to catch them.  The burbot and grey mullet are occasionally eaten, but they taste of mud, and are not in request.

Some years ago the experiment was made, with success, of introducing into Mauritius the Osphromenus olfax of Java, which has also been taken to French Guiana.  In both places it is now highly esteemed as a fish for table.  As it belongs to a family which possesses the faculty, hereafter alluded to, of surviving in the damp soil after the subsidence of the water in the tanks and rivers, it might with equal advantage be acclimated in Ceylon.  It grows to 20 lbs. weight and upwards.]

Of eight of these, which were from the Mahawelliganga, and caught in the vicinity of Kandy, five were carps; two were Leucisci, and one a Mastacembelus (M. armatus, Lacep); one was an Ophiocephalus, and one a Polyacanthus, with no serrae on the gills.  Six were from the Kalanyganga, close to Colombo, of which two were Helostoma, in shape approaching the Chaetodon; two Ophiocephali, one a Silurus, and one an Anabas, but the gills were without denticulation.  From the still water of the lake, close to the walls of Colombo, there were two species of Eleotris, one Silurus with barbels, and two Malacopterygians, which appear to be Bagri.

The fresh-water Perches of Europe and of the North of America are represented in Ceylon and India by several genera, which bear to them a great external similarity (Lates, Therapon).  They have the same habits as their European allies, and their flesh is considered equally wholesome, but they appear to enter salt-water, or at least brackish water, more freely.  It is, however, in their internal organisation that they differ most from the perches of Europe; their skeletons are composed of fewer vertebrae, 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 ichthyological work[1]; it attains to the length of seven inches.

[Footnote 1:  Holocentrus quadrilineatus, Bloch.  It is allied to Helotes polytoenia, Bleek., from Halmaheira which it can be readily distinguished by having only five or six blackish longitudinal bands, the black humeral spot being between the first and second; another blackish blotch is in the spinous dorsal fin.  There are two specimens in the British Museum collection, one of which has recently arrived from Amoy; of the other the locality is unknown.  See GUeNTHER, Acanthopt.  Fishes, vol. i. p. 282, where mention of the black humeral spot has been omitted.]