chap, viii.] BIRDS. . 161 



as indications of past changes in physical geography. A large 

 proportion of the remains belong to aquatic or wading types, 

 and as these have now often a world-wide range, the occurrence 

 of extinct forms can have little bearing on our present inquiry. 

 There are, however, a few interesting cases of extinct land-birds 

 belonging to groups now quite strangers to the country in which 

 they are found ; and others scarcely less interesting, in which 

 groups now peculiar to certain areas are shown to have been 

 preceded by allied species or genera of gigantic size. 



Palcearctic Region and N. India. — In the caves and other 

 Post-Pliocene deposits of these countries, the remains of birds 

 almost all belong to genera now inhabiting the same districts. 

 Almost the only exceptions are, the great auk and the 

 capercailzie, already mentioned as being found in the Danish 

 mounds ; the latter bird, with Tetrao albus, in Italian caverns ; 

 and a species of pheasant (Phasianus) said to have occurred in 

 the Post- Pliocene of France, considerably west of the existing 

 range of the genus in a wild state. 



In the preceding Pliocene deposits, but few remains have 

 been found, and all of existing genera but one, a gallinaceous 

 bird (Gallus bravardi) allied to the domestic fowl and peacock. 



The Miocene beds of France and Central Europe have pro- 

 duced many more remains of birds, but these, too, are mostly of 

 existing European genera, though there are some notable excep- 

 tions. Along with forms undistinguishable from crows (Corvus), 

 shrikes (Lanius), wagtails (Motacilla), and woodpeckers (Picus), 

 are found remains allied to the Oriental edible-nest swift (Col- 

 localia) and Trogon ; a parrot resembling the African genus 

 Psittacus ; an extinct form Necrornis, perhaps allied to the 

 plantain-eaters (Musophaga) ; Homalophus, doubtfully allied to 

 woodpeckers, and Limnatornis to the hoopoes. The gallina- 

 ceous birds are represented by three species of pheasants, some 

 very close to the domesticated species ; Palccoperdix allied to the 

 partridges ; and Palceortyx, small birds allied to the American 

 genus Ortyx, but with larger wings. There are also species of 

 Pterocles allied to living birds, and a small pigeon. There are 

 numerous living genera of Accipitres ; such as eagle {Aquila), 



