Indo-Malayan

“Wallace’s line” dividing the Indo-Malayan and Austro-Malayan sub-regions is frequently transgressed in the range of Malayan insects.

The species are about equally divided between the Indo-Malayan region and tropical America, only one species being common to both.

So far as the species not peculiar to the islands are concerned, the influence of the Indian sub-region has vastly predominated; and if we look to the genera the preponderance is still more marked, and thus it seems difficult to avoid the conclusion that the ornis has altogether a very far stronger affinity with that of the Indian region than with those of either the Indo-Burmese or the Indo-Malayan.

In spite of what is to be expected from their position, the islands derive the bulk of their species from the distant Indian region, while the Indo-Burmese and Indo-Malayan regions are represented to a far less degree.

They are Indo-Malayan ferns with creeping rhizomes and long-stalked, fan-shaped, forked, leathery fronds.