84 0)1 the Geographical Distribution of the Lacertilia. 



didas is represented in its southern parts ; this great island 

 must be regarded as the debatable ground between the Aus- 

 tralian and Oriental Regions. But, as observed above, there 

 is, as regards the Lizards, no fundamental difference between 

 the two ; they form a single great region, which may be 

 divided into several subregions, but not into two primary 

 divisions, as required for other groups of animals. 



4. The Australian Region. — Only five families occur — two 

 cosmopolitan (Geckonidse and Scincidge), two in common with 

 Asia and Africa (Agamidse and Varanid^), and one charac- 

 teristic (Pygopodidse). In New Guinea occurs the small 

 family Dibamidge ; and the Fiji Islands possess a genus of 

 Iguanoids, Brachylojphus^ the nearest ally of which is perhaps 

 the West-Indian Cyclura. The bulk of the fauna consists of 

 the Geckonidffi and Scincidse. The latter, as regards number 

 of species and variety of forms are not surpassed or even 

 equalled in any other part of the world, and the former are 

 well represented, although less so than in the Oriental Region. 

 In the islands of the South Pacific, New Zealand included, 

 these two families only are found, but represented by nume- 

 rous species, some of which are types of peculiar genera, 

 usually showing but remote afiinity to the continental forms. 

 The Agamoids are mostly terrestrial, some semi-arboreal 

 and semiaquatic. Special affinity with the Oriental Region 

 is shown in the genera Physignathus (four species in Aus- 

 tralia, two in Siam and Cochin China) and Gonyocephalus 

 (numerous throughout the Malayan and Papuasian islands, 

 two species in Queensland). One of the most remarkable 

 features of Australia is the small number of families, it being 

 in this respect inferior to Europe, which possesses represen- 

 tatives of seven, a remark which applies also to the Batra- 

 chians, of which Australia has four families and Europe 

 seven. 



Thus we arrive at the conclusion tliat the zoo-geographical 

 regions generally in use, and especially their degree of rela- 

 tionship to one another, receive little support from the study 

 of the distribution of Lizards ; that the distribution in zones, 

 which is so satisfactorily shown by the Batrachians and the 

 freshwater Fishes, is contrary to the plainest evidence as 

 regards Lizards, which at the present time range more 

 according to longitude ; that the two great divisions originally 

 proposed by Mr. Sclater, and derived from the study of 

 passerine birds, hold good ; and that, if a division of the 

 world had to be framed according to the lizard-faunas, the 

 primary divisions would be the following : — 



