Butterflies of Mauritius and Bourbon. 431 
any tropical island. Bourbon is altogether different, deep 
water and heavy breakers come straight on to the beach 
without any natural breakwater, and the shore is covered 
with huge water-worn boulders and rounded pebbles, with 
an entire absence of marine life. In the one case we have 
quiet seas and intense natural beauty, in the other the 
whole coast, so far as I saw it, is subject to the full and 
eternal swell of the Indian Ocean. 
In physical features Bourbon is also different to 
Mauritius; though very much of the same’size or rather 
smaller, it is distinctly mountainous, and evidences of 
voleanic action are even more marked. One can get a 
good idea of the country by placing three circles in a 
triangle and touching each other, with the base to the 
west. These three circles, each about five miles in 
diameter, represent three extinct volcanoes; place another 
circle to the south of these but separated from them and 
this will mark the position of the present active crater 
which is on the coast. The centre of the easternmost 
crater is exactly the centre of the island, and the part 
where the three circles meet forms the main mountain 
range running north and south, the highest point, the 
Piton des Niéges, being over 10,000 feet above the level 
of the sea and covered with snow for a considerable portion 
of the year. This trend of the hills gives a very different 
character to the climate on either side of it. The trade- 
winds striking the cold eastern flanks of these mountains 
deposit their moisture in heavy rain, the western portion 
only receiving occasional showers on their hill-sides, the 
coast rarely receiving any rain at all. It is a country 
where I fully hoped to find species of Teracolus and Acrea, 
if illness had not put a very decided veto on any exploration 
Thad contemplated. The chief villages, I cannot call them 
towns, are built at the bottom of the aforesaid three craters, 
the eastern one being Salazie, the western Cilaos, and the 
northern Mafitte. It is a peculiar experience living in 
such a situation, and though very beautiful from the 
verdure of the numerous smaller hills scattered over the 
floor of the crater, and the fantastic appearance of the 
cliffs forming its edge, one’s view is limited to the sur- 
rounding rugged cliffs, and after a short residence I had an 
almost irresistible desire to climb up and peep over the 
other side, much like a kitten at the bottom of a basket. 
There is but one road to each of these craters, that up the 
TRANS. ENT. SOC. LOND. 1907.—PART IV. (FEB. 08) 29 
