28 SPOLIA ZEYLANICA. 
To account for the numerous peculiar species in Ceylon, we 
must now suppose a break in this intercourse lasting for some 
little time. It must, therefore, have begun soon after the 
close of the glacial epoch, and quite possibly its beginning was 
contemporaneous with the close of that period. 
As the climate grew warmer, the Himalayan birds would 
retreat northwards again, or make for the higher elevations 
and the dampest forests. 
When this northerly retreat began some of the species 
might have found themselves cut off, not only by a belt of 
low-country forest in which tropical conditions were again 
beginning to prevail, but also by the separation of Ceylon from 
the mainland. This would account for the presence among 
our birds of such isolated short-flight species as Cyanops 
flavifrons (the Yellow-fronted Barbet), Cissa ornata (the Ceylon 
Magpie), and Acmonorhynchus vincens (Legge’s Flower-pecker), 
whereas these genera do not occur in the Malabar tract. 
Either their retreat was not cut off from the Malabar hills, or 
they have since died out there in the struggle for existence. 
We then come to a period fairly long in time, though short 
geologically speaking, in which Ceylon was an island of . 
curtailed dimensions. The low-lying “ arid maritime belts ” 
of the north-west and south-east would be under water. The 
rest of the Island would be populated with an indigenous 
fauna of the Malabar type. The climatic conditions would 
be much the same as those of the present day. Migrants and 
other birds which could cross the intervening sea would come 
to our shores, or be carried by the monsoons against their 
will, and if the conditions were to their liking would settle 
down here. 
Within a measurable distance of historic times re-elevation 
set in, and continuous communication was again established 
with India across Adam’s Bridge. The dry-country “ Car- 
natic ’’ type of birds, which heretofore had been wanting in 
Ceylon, would find in the newly elevated sandy tracts localities 
in which they could flourish, and, of course, the invasion would 
be accompanied by a good many birds common to Malabar 
and the Carnatic. This invasion would account for the fact 
that in so many of our families and genera you will find a 
