172 
MR. A. R. WALLACE ON THE ZOOLOGICAL 
grey ; veins black ; pobrachial vein forming an obtuse angle at its 
junction with the diseal transverse vein, the latter very oblique, parted 
by little more than half its length from the border , and by nearly thrice 
its length from the praebrachial transverse ; halteres whitish. Length 
of the body 2s lines j of the wings lines. 
Fam. PIIORID^E, Saliday. 
Gen. Phora, Latr. 
238. Phora bifasciata, n. s. Fam. Atra, subtus flavescenti-alba, 
antenuis fulvis, abdomine lauceolato, fasciis duabus apice pedibus 
halteribusque flavescenti-albis, pedibus posticis nigris basi flaveseenti- 
albis, tarsis intermediis nigricantibus, alis cinereis. 
Female. Deep black, yellowish white beneath ; antennae tawny ; abdo- 
men lanceolate, much longer than the thorax ; sides elevated, a broad 
basal yellowish white band, and a narrower one beyond the middle, 
tip also yellowish white ; anterior legs and halteres yellowish white, 
middle tarsi blackish, hind femora with the basal half yellowish white ; 
wings cinereous, veins black, pale at the base ; costal vein ending at 
a little beyond half the length of the wing ; radial cubital, praebrachial, 
and pobrachial veins parallel and equally distinct. Length of the 
body 2-21 lines ; of the wings 5-6 lines. 
On the Zoological Geography of the Malay Archipelago. By 
Alfred 11. Wallace, Esq. Communicated by Charles 
Darwin, Esq., F.R.S. & L.S. 
[Read Nov. 3rd, 1859.] 
In Mr. Sclater’s paper on the Geographical Distribution of Birds, 
read before the Linnean Society, and published in the ‘ Proceed- 
ings ’ for February 1858, he has pointed out that the western 
islands of the Archipelago belong to the Indian, and the eastern 
to the Australian region of Ornithology. My researches in these 
countries lead me to believe that the same division will hold good 
in every branch of Zoology ; and the object of my present com- 
munication is to mark out the precise limits of each region, and 
to call attention to some inferences of great general importance as 
regards the study of the laws of organic distribution. 
The Australian and Indian regions of Zoology are very strongly 
contrasted. In one the Marsupial order constitutes the great mass 
of the mammalia, — in the other not a solitary marsupial animal 
exists. Marsupials of at least two genera (Cuscus and Belideus) 
are found all over the Moluccas and in Celebes; but none have 
