2 SPOLIA ZEYLANICA. 
absence of any large accumulations of sedimentary rocks, 
that throughout the manifold variations of the earth’s surface 
during the changing geological periods the main part of Ceylon 
was never submerged for any length of time. As it is the 
animal and vegetable fossils of the sedimentary rocks which 
give us the information of the age of the strata, our information 
regarding Ceylon is almost a blank. The only strata in the 
Island which, to my knowledge, contain fossils are recent 
shell beds on the north, north-west, and south-east coasts, 
and certain river gravels here and there through the Island. 
Apart from there being so few rocks which can give us fossils, 
the study of geology in Ceylon is rendered difficult by the fact 
that in most places the strata are so covered with jungle under- 
growth and topsoil that their outcrops are hidden, and one 
cannot get at them to study them. The present Mineralogical 
Survey is largely for economic purposes, and is concerned more 
with petrography, or the composition of the rocks, than with 
the physical geology of the Island as a whole. 
Consequently, in order to throw light on the recent geological 
history of Ceylon, we are thrown back mainly upon the study 
of its fauna and flora, and upon the relations they bear to 
those of the adjacent mainland. 
|. Now, there is no doubt from the close connection between 
our fauna and that of Southern India that Ceylon is a mere 
appanage of that land, and has not been separated from it for 
any tremendous length of time. 
Wallace, who was one of the great pioneers in the science of 
zoo-geography, in his “‘ Geographical Distribution of Animals,” 
published in 1876, divided the world into six main zoological 
regions. The Palearctic Region roughly comprised Europe, 
Africa north of the Sahara, and Asia north of the Himalayas. 
The Ethiopian Region took in the rest of Africa. The Oriental 
Region contained India, Further India, Southern China, and 
the islands of the Malay Archipelago, down to the famous 
‘“Wallace’s Line,” which separates Bali from Lombok and 
Borneo from Celebes. The islands beyond Wallace’s line, 
together with Australasia, formed the Australian Region ; while 
North and South America were divided into the Nearctic and 
Neotropical Regions. 
