ecies of fruit-bat (_Pteropus comorensis_), a group which ranges
from Australia to Asia and Madagascar but is unknown in Africa. Of
land-birds forty-one species are known, of {429} which sixteen are peculiar
to the islands, twenty-one are found also in Madagascar, and three found in
Africa and not in Madagascar; while of the peculiar species, six belong to
Madagascar or Mascarene genera. A species of Chameleon is also peculiar to
the islands.

These facts point to the conclusion that the Comoro Islands have been
formerly more nearly connected with Madagascar than they are now, probably
by means of intervening islets and the former extension of the latter
island to the westward, as indicated by the extensive shallow bank at its
northern extremity, so as to allow of the easy passage of birds, and the
occasional transmission of small mammalia by means of floating trees.[105]

_The Seychelles Archipelago._--This interesting group consists of about
thirty small islands situated 700 miles N.N.E. of Madagascar, or almost
exactly in the line formed by continuing the central ridge of that great
island. The Seychelles stand upon a rather extensive shallow bank, the
100-fathom line around them enclosing an area nearly 200 miles long by 100
miles wide, while the 500-fathom line shows an extension of nearly 100
miles in a southern direction. All the larger islands are of granite, with
mountains rising to 3,000 feet in Mahe, and to from 1,000 to 2,000 feet in
several of the other islands. We can therefore hardly doubt that they form
a portion of the great line of upheaval which produced the central granitic
mass of Madagascar, intervening points being indicated by the Amirantes,
the Providence, and the Farquhar Islands, which, though all coralline,
probably rest on a granitic basis. Deep channels of more than 1,000 fathoms
now separate these islands from each other, and if they were ever
sufficiently elevated to be united, it was probably at a very remote epoch.

The Seychelles may thus have had ample facilities for receiving from
Madagascar such immigrants as can pass over narrow seas; and, on the other
hand, they were equally favourably situated as regards the extensive Saya
de Malha and Cargados banks, which were probably once {430} large islands,
and may have supported a rich insular flora and fauna of mixed Mascarene
and Indian type. The existing fauna and flora of the Seychelles must
therefore be looked upon as the remnants whi