24 SPOLIA ZEYLANICA. 
To sum up the situation in a few words, the Malabar affinity 
in the wet zone is shown by close correspondence of type ; 
the Carnatic affinity in the dry zone by complete identity of 
species. 
How are we to account for this dual distribution of birds ? 
I do not think it can easily be contended that the main 
Malabar element in the Kandyan districts invaded the Island 
across an intervening dry Carnatic zone. If this had been 
the case, there surely would have been more connecting links 
in the intervening region ? 
Nor, again, does it appear likely that the Malabar element in 
the Kandyan districts and the Carnatic element in the north 
of the Island developed side by side. In this case the 
separation of Ceylon from India would be a mere geological 
incident, without any serious zoo-geographical import. It 
would imply that Ceylon for some time had been a mere 
prolongation southwards of the Malabar and Carnatic tracts, 
and I do not think that this is a satisfactory explanation of 
the distribution of our birds. 
If this supposition were correct, one would expect that the 
whole of Blanford’s Northern Region of Ceylon—+.e., the whole 
of the east of the Island from Jaffna to Tangalla—would have 
a more or less uniform Carnatic element ; whereas, as a matter 
of fact, that element diminishes considerably as one travels 
southward. One would also expect that the species peculiar 
to the Island would be more equally distributed. 
I venture to suggest as the most satisfactory solution of the 
problem the hypothesis that the distribution of our birds can 
be explained by assuming the Malabar and Himalayan elements 
to belong to an older period, when our fauna had an uninter- 
rupted communication with the fauna of the Malabar coast, 
and when the Carnatic element, due to a later invasion, 
was as yet unrepresented. 
This uninterrupted communication with the Malabar coast 
was afterwards broken, and almost all communication for 
birds of short flight between Ceylon and the mainland was cut 
off by a subsidence of the earth’s surface, which would have 
submerged the north-west and south-east of our Island and a 
fairly wide strip of the opposite mainland. Quite a small 
