6 SPOLIA ZEYLANICA. 
will throw some light on the geological changes which have 
separated Ceylon from South India, I will leave all discussion 
as to their significance until I have summarized that distri- 
bution. 
In the course of his paper already alluded to, Dr. Blanford 
has given a complete tabulation of all the genera of vertebrate 
animals found in the nineteen tracts of the Indian Empire, ° 
and the differences and affinities shown in these tables are 
the bases on which he has founded his conclusions. He has 
stopped short at generic and not gone into the further detail 
of specific differences, partly because the work would have 
been too enormous, and partly because differences in species are 
not so sure a guide as differerces in genera. 
He has also attached far mcre weight to the distribution of 
mammals than to that of other vertebrates, because the means 
of dispersal in the case of mammals is more limited than in 
other orders. They cannot fly over arms of the sea, nor can 
they cross mountain ranges as easily as birds. 
However, as I am not competent to deal with any vertebrates 
but birds, as my investigations cover a more limited area, 
and as the differences between the birds cf Ceylon and those 
of the adjoining tracts are largely confined to differences 
merely of species and not of genera, I must go into greater but 
less sure detail, and take as my unit the species. 
First of all it is necessary to examine the division of Ceylon 
into zoo-geographical districts. 
Blanford divides the Island into two tracts as described 
above, but for a more detailed examination one cannot do 
better than follow the divisions given by Captain Legge in his 
Introduction to the “‘ Birds of Ceylon.” He divides the 
Island into four districts: the dry forest areas of the north 
~ and south-east ; the arid maritime belt of the north-west coast, 
with which he groups the similar belt on the south-east ; the 
damp western forest region ; and the hill zone of the Kandyan 
districts. 
The first two make up Blanford’s Carnatic tract of Ceylon, 
and the last two his Malabar tract. 
Now, it is true that the south-east “ arid maritime belt ”’ is 
exactly suited to the dry-country birds which inhabit the 
