Transtt-Expedition Naturalists at Rodriguez. 367 
I have paid special attention to the Palms and Pandani. Of 
the former there are three species indigenous—one of the genus 
Latania, and two belonging to the genus Areca. The Pandani 
present much greater difficulty in their determination ; and I do 
not yet feel in a position to fix definitely the number of species, 
although I rather incline to the idea that there are only two true 
species. My collection of the plants of the island now numbers 
about 450 species, of which about three fourths are Phenogams. 
T have made observations with the view of discriminating between 
the indigenous and introduced vegetation, but there are several 
plants regarding which I am doubtful. I have not yet succeeded 
in finding any marine Phenogams ; hitherto, however, I have not 
devoted much time to the marine flora. There are no tree ferns 
on the island; at least I have seen none, and, as far as I can 
learn, none of the inhabitants have seen any. Ferns are repre- 
sented by about two dozen species ; mosses and freshwater alge 
are not abundant, but lichens are very numerous, both as species 
aud as individuals. This flora is by no means so extensive as I 
had expected ; but the survey of the island just concluded by the 
officers of the ‘ Shearwater’ shows the island is only about half the 
size it was previously supposed to be, it being only 11 miles long 
by 4 miles broad. The island is a volcanic one, consisting of a 
succession of lava-flows, radiating from one or more foci in the 
centre of the island, and now worn away so as to form a series of 
more or less parallel ridges, separated by deep ravines. These 
lava-flows are composed chiefly of a dark compact basalt, not un- 
frequently becoming porphyritic, and commonly exhibiting a marked 
columnar structure ; and I have counted as many as twelve such 
flows, lying one above the other, separated severally, either by beds 
of conglomerate, or by beds of laterite, or variously coloured clayey 
beds. Granite and sandstone do not occur in the island. At the 
east and at the west ends of the island occur the only non-volcanic 
rock in the island, namely coralline limestone, extending in huge 
sheets over many acres of land, and also occurring in detached 
patches on the top of the basalt, often nearly a mile from the 
sea. On the northern and southern sides of the island it does 
not occur; but on the southern side may be seen some raised 
beaches, marking upheaval there, as does the coralline limestone 
at the east and west sides. Zeolites are common in the basalt 
in many places, as also several other minerals. The whole rocks 
of the island are permeated by iron. This report is very brief ; 
but I have abstained from entering into details regarding the 
botany and geology of the island, leaving that for the full report 
to be given in on my return. I trust, however, the above is suffi- 
cient to show that I have made some progress towards accomplishing 
the objects for which I was sent out here. 
I am, Sir, 
To the Secretary of Yours faithfully, 
the Royal Socrety. Is. Bayitey BALrour. 
