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 local