Flora of the Ceylon Littoral. 49 
Limnantliemum, etc.) form a gradual transition from the thick 
vegetation of the banks to the open water of the river. 
The river at Kalutara thus shows a more pronounced 
conglomeration of different types of vegetation than either of the 
preceding rivers ; not only do the different littoral formations 
intermingle freely, but typical inland low country plants play an 
important part on the banks at no great distance from the mouth. 
Probably, if we could have gone further up stream, it would have 
been found that in the Kalu Ganga the inland jungle dominates the 
river-banks to the exclusion of the littoral formations much sooner 
than in either of the preceding rivers. 
Balapitiya. 
As a last example of the types of vegetation under discussion a 
brief description of the lagoon at Balapitiya, which is situated 
about four miles to the north of Ambalangodda, may be given. 
The lagoon does not open directly into the sea like that at 
Negombo, but is connected with it by a narrow river about half a 
mile in length. 
The banks of this river are clothed by a dense growth of 
Rhizophova conjugata and Bruguiera gymnorhiza, with splendidly 
developed root-systems ; in between are isolated specimens of 
Sonncmtia and Calophyllum, and a single tree of Heritieva was also 
seen here. Acanthus ilicifolius is however practically wanting, 
except for a small patch of it near the mouth. There were no 
floating plants in the river when we visited it, and its vegetation is 
altogether of a remarkably uniform character. It is the best 
example we have seen in Ceylon of a pure mangrove-vegetation 
fringing the banks of a river within a short distance of the sea 
—indeed the mangroves are much nearer the latter here than even 
at Negombo. The lake is a very extensive piece of water, pro¬ 
jecting inland in several directions and containing several small 
islands, some of the more rocky of which are covered with a growth 
of Cleichenia dicliotoma. At numerous points round about the lake 
Rhizophova and even more commonly Bruguiera are well developed 
and their abundant presence quite recalls the lagoon at Negombo, 
which has become classical through Schimper’s description. In 
the lake at Balapitiya, Sonneratia is also very commonly 
represented, but the vegetation is by no means a pure mangrove- 
formation,—in fact far less so than at Negombo—for here and 
there we get Pandauus and Susum occurring, and Chrysodium 
