166 
MANGROVE SWAMPS. 
character, with oxide of iron, oxide of manganese, 
carbonate of iron, supercarburetted iron, and the pre- 
cipitation of substances chemically dissolved.” 
The following shells were found on the shore : — 
Donax, Solen, Lima, Conus, and Mactra, 
In the swampy parts of the right bank, the mangrove, 
Rhyzophora, abounds, with its peculiar fructification. 
There are two species of this tree, one growing very low, 
and having a white wood ; the other is a rather high 
tree, with a fine red wood, which burns well as fLiel. 1 he 
bark is very astringent. The numerous arching roots 
of this tree are favourable for the deposition of sand and 
mud. 
In the woods on this bank, which were visited for the 
purpose of procuring specimens, the water was upwards 
of two feet deep in most parts, and the air close and 
confined. The greater portion of the underwood was 
Rhyzophora, or mangrove. The stillness of this soli- 
tary region was occasionally broken by the Halcyon 
Senegalensis, or grey-headed king-hunter, which in its 
rich blue and cinereous grey plumage, flitted from tree to 
tree, almost the sole occupant of the place. Near the 
outskirts, we met one of the most interesting species of 
Macrodypterix, the pennant-winged night-jar, with its 
long filiform feather attached to each wing. 
On returning to the boat, a new and beautiful species 
of swallow, the Hirundo nigrita, since figured in 
Mitchell’s superb work on the genera of birds, was dis- 
covered performing its rapid evolutions over a placid pool 
