442 ZOOLOGICAL GEOGKAPHY. [part in. 



longing to a different family, the Casurariidaa* To the right are 

 a pair of crested pigeons {Ocyphaps lophotes), one of the many sin- 

 gular forms of the pigeon family to which the Australian re- 

 gion gives birth. In every other part of the globe pigeons are 

 smooth-headed birds, but here they have developed three dis- 

 tinct forms of crest, as seen in this bird, the crowned pigeon 

 figured in Plate X., and the double-crested pigeon (Lopholcemus 

 antardicus). The large bird on the tree is one of the Australian 

 frog-mouthed goat-suckers (Podargits strigoides), which are 

 called in the colony " More-pork," from their peculiar cry. They 

 do not capture their prey on the wing like true goat-suckers, but 

 hunt about the branches of trees at dusk, for large insects, and 

 also for unfledged birds. A large kangaroo {Macropus giganteus) 

 is seen in the distance ; and passing through the air, a flying 

 opossum (Petaurus sciureus), a beautiful modification of a marsu- 

 pial, so as to resemble in form and habits the flying squirrels 

 of the northern hemisphere. 



III. Hie Pacific Islands, or Polynesian Sub-region. 



Although the area of this sub-region is so vast, and the 

 number of islands it contains almost innumerable, there is a 

 considerable amount of uniformity in its forms of animal life. 

 From the Ladrone islands on the west, to the Marquesas on the 

 east, a distance of more than 5,000 miles, the same characteristic 

 genera of birds prevail ; and this is the only class of animals on 

 which we can depend, mammalia being quite absent, and reptiles 

 very scarce. The Sandwich Islands, however, form an exception 

 to this uniformity; and, as far as we yet know, they are so 

 peculiar that they ought, perhaps, to form a separate sub-region. 

 They are, however, geographically a part of Polynesia; and a 

 more careful investigation of their natural history may show 

 more points of agreement with the other islands. It is therefore 

 a matter of convenience, at present, to keep them in the Poly- 

 nesian sub-region, which may be divided into Polynesia proper 

 and the Sandwich Islands. 



Polynesia proper consists of a number of groups of islands of 

 some importance, and a host of smaller intermediate islets. 



