18/8.] MR. D. G. ELLIOT ON THE GENUS PTILOPUS. 515 



of its habitat, which also had become islands. In considering the 

 peculiarities of the geographical distribution of these birds, the 

 great physical changes that have taken place in that portion of the 

 globe over which they are dispersed must always be borne in mind. 



The members of the genus Ptilopus are found in only two of the 

 zoogeographical regions of the earth, viz. the Oriental and Aus- 

 tralian. Of these the latter contains by far the great majority of 

 the species ; and, to judge from the material at present available, the 

 Papuan group of the Austro-Malayan Subregion is apparently the 

 head quarters of the genus, The Polynesian Subregion also 

 possesses many species ; but they are altogether of a different style 

 of plumage, and constitute almost a division by themselves. 



I commence the review of this portion of my subject with the 

 most easterly group of the Pacific islands (in the Polynesian Sub- 

 region of the Australian Region) in which any members of this genus 

 are found, viz. the Marquesas. But two species are met with 

 among these islands — the Pt. dupetit-thouarsii, on Christine Island, 

 and the Pt. mercieri, from Nuka-hiva. Both of these are very 

 distinct from all others known. I have described Pt. pictiventris as 

 from Nuka-hiva of the Marquesas ; but, for the reasons I give under 

 the head of this species, I believe that locality to be an error, and that 

 the bird in question is a native of the Samoan Islands only. To the 

 south-west of the Marquesas lies the Pomatu archipelago, which is 

 as yet hardly known in an ornithological sense. But one species of 

 Ptilopus has been recorded from there, Pt. coralensis, found on 

 Carlshoff Island. South of the Pomatu group lies the island of 

 Rapa. Here has been procured probably the most important 

 member of this genus, Pt. huttoni. To the west of Pomatu 

 are the Society Islands, upon only two of which have any species 

 of Ptilopus been procured, viz. P. chrysog aster, upon Huahaine, and 

 Pt. taitensis in Otaheite. To the south-west of this last is Cook's 

 Archipelago, where Pt. chalcurus has been obtained on Harvey 

 Island. It is still doubtful if this bird is specifically distinct from 

 Pt. coralensis of the Pomatu group. If the identity of those 

 two could be established, it would be an interesting and important 

 fact, since the two clusters of islands are not only separated by miles 

 of ocean, but several distinct forms of Ptilopus are found upon 

 the intervening archipelagos, none of which, so far as we know, 

 are particularly related to Pt. chalcurus. Upon Rarotonga island 

 has been procured Pt. rarotongensis ; and these two species are 

 all that have as yet been found in this group. Savage Island, lying 

 between Cook's Archipelago and the Friendly group, contains three 

 species — Pt. purpuratus, Pt. pictiventris and Pt. rarotongensis. 

 Passing on to the westward we reach the Tonga Islands, among 

 which five species of Ptilopus dwell, a number exceeded in only one 

 of the Pacific groups, viz. the Fijis. On Tonga-Tabou all the 

 species occur — Pt. chrysogaster, Pt. apicalis, Pt. pictiventris, Pt. 

 purpuratus, and Pt. perousii. Harpai contains Pt. perousii and 

 Pt. purpuratus ; and this last has also been procured at Eua and 

 Ninafou, the last the most northern of them all. North of the 



