276 MR. A. R. WALLACE ON THE [June 28, 
able exception being the northern Moluccas (Gilolo, Batchian, and 
Morty), which do not seem to possess it. The small species in which 
the sexes differ, and which are best placed with Charmosyna, are, 
however, found in these islands. Celebes, Sumatra, Timor, and Aru 
have each species of J'’richoglossus peculiar to them. 
The Platycerci are but poorly represented in the Austro-Malayan 
Islands, and seem to be hardly at home in the damp tropical forests. 
They have the same range as the Lories, but extend also to the Sulla 
Islands ; and a species of an Australian form inhabits Timor. 
We now come to the Cockatoos, another most characteristic Au- 
stralian form which ranges over the whole Australian region, except 
the Pacific Islands, marking out the limits of that region in the 
Malay archipelago by reaching Celebes and Lombock, and sending 
one species into the Philippine Islands, which are considered to be- 
long to the Indian region. We must first remark that the genus 
Cacatua has a wider range in the Australian region than any other, 
occupying every island in the Australian and Austro-Malayan sub- 
regions, and always existing in considerable abundance. This indi- 
cates a dominant group, which has great capacities for increase and 
self-preservation and great powers of diffusion. It is therefore not 
wonderful that one species should be found to have penetrated be- 
yond its true home. That this was due to greater facilities for emi- 
gration at a comparatively recent epoch in the existence of the genus, 
is indicated by the fact that, whereas throughout the rest of the ar- 
chipelago the species of Cacatua are much restricted, each island or 
small group of islands possessing its peculiar form, in the Philip- 
pines one species ranges over the whole of that extensive region. 
One of the most interesting genera of Parrots in the archipelago 
and in the world is undoubtedly Prioniturus, which exhibits the 
only instance in the whole order of a spatulate or racket-shaped tail 
like that of the Motmot; but in this case the perfectly bare and 
smooth shaft is produced by a natural process of growth, as in the 
King Bird of Paradise. The four species of this remarkable genus 
are equally divided between Celebes and the Philippines, and present 
a most curious case of the restricted range of a well-marked group. 
An exactly analogous case among Mammalia is the genus Cynopi- 
thecus, atorm of baboon completely unlike anything else in the East, 
and confined te the Philippines, Celebes, and the small adjacent 
island of Batchian, into which it was probably introduced. While 
these two groups of islands have thus evidently had once a closer 
connexion than at present, they both possess a striking individuality 
which separates them from the primary regions to which they re- 
spectively belong. The Philippines stand alone in the Indian region 
by the absence of all large carnivora and pachyderms, as well as of 
Apes and Monkeys, (in birds) by the absence of Phasianide (which 
are preeminently Indian) and by the presence of Megapodius (which 
is as preeminently Australian), by having no Trogons, Paleornis or 
Eurylemide, and by possessing Cacatua, Tanygnathus, and Cyclo- 
psitta. Just in a parallel manner is Celebes distinguished by the 
presence of peculiar forms of Antelope and Baboon, and by species 
