334 ZOOLOGICAL GEOGRAPHY. [PART III. 
possess, for passing over a considerable width of sea. We must 
conclude, therefore, that these islands do not owe their exist- 
ing fauna to an actual union with the mainland; but it is pro- 
bable that they may have been formerly more extensive, and 
have then been less distant from the continent than at the 
present time. 
The Nicobar Islands, usually associated with the Andamans, 
are less known, but present somewhat similar phenomena. They 
are, however, more Malayan in their fauna, and seem properly 
to belong to the Indo-Malay sub-region. 
Formosa.—This island has been carefully examined by Mr. 
Swinhoe, who found 144 species of birds, of which 34 are peculiar. 
There is one peculiar genus, but the rest are all Indo-Chinese, 
though some of the species are more allied to Malayan than to 
Chinese or Himalayan forms. About 30 species of mammalia 
were found in Formosa, of which 11 are peculiar species, the rest 
being either Chinese or Himalayan. The peculiar species belong 
to the genera Talpa, Helictis, Scivropterus, Pteromys, Mus, Sus, 
Cervus, and Capricornis. A few lizards and snakes of conti- 
nental species have also been found. These facts clearly indicate 
the former connection of Formosa with China and Malaya, a 
connection which is rendered the more probable by the shallow 
sea which still connects all these countries. 
Hainan.—tThe island of Hainan, on the south coast of China, 
is not so well known in proportion, though Mr. Swinhoe col- 
lected 172 species of birds, of which 130 were land-birds. Of 
these about 20 were peculiar species ; the remainder being either 
Chinese, Himalayan, or Indo-Malayan. Mr. Swinhoe also ob- 
tained 24 species of mammalia,.all being Chinese, Himalayan, 
or Indo-Malayan species except a hare, which is peculiar: This 
assemblage of animals would imply that Hainan, as might be 
anticipated from its position, has been more recently separated 
from the continent than the more distant island of Formosa. 
IV. Indo-Malaya, or the Malayan Sub-region. 
This sub-region, which is almost wholly insular (including 
only the Malayan peninsula on the continent of Asia), is equal, if 
