DISTRIBUTION. 9 



and subtropical zones are the real home of the reptilian type, which there has 

 reached its greatest development as regards size and variety of forms. In the 

 north, Chelonians advance only to 50° latitude in the Western and to 56° in the 

 Eastern Hemisphere ; lizards to about 56° in British Columbia, and close to the 

 Arctic Circle in Europe ; while snakes disappear some degrees before the lizards. 

 Also in the south, lizards extend into higher latitudes than snakes, namely, to the 

 Straits of Magellan, whilst the latter do not seem to have advanced beyond 40° 

 south latitude, and Chelonians to 36°." 



Of the various zoological regions into which the globe has been divided, the 

 Oriental or Indian region, according to the same observer, is characterised by the 

 number of fresh- water soft-tortoises l and S-necked tortoises, 1 land-tortoises being 

 scarce. Crocodiles, inclusive of the characteristic long-necked garials, are numerous, 

 as are lizards and snakes — especially pythons. Africa is comparatively poorly off* 

 for Reptiles, although characterised by its numerous land-tortoises, soft-tortoises, 

 and side-necked tortoises ; x the crocodiles being represented only by members of 

 the typical genus ; while lizards and snakes are comparatively numerous. Among 

 the lizards, monitors, and among the snakes, pythons, are common to the Oriental 

 and African regions ; while half of the exclusively Old World group of chamseleons 

 are African. Madagascar is even more remarkable for the number of its 

 chamseleons; its land and side-necked tortoises are numerous, although soft- 

 tortoises, as in South America, are absent ; there is one crocodile ; and among the 

 lizards the South American group of iguanas is abundant; while the snakes, 

 among which none is poisonous, are also of a South American type. In the 

 warmer parts of the Euro-Asiatic region (exclusive of India, etc.) the reptile fauna 

 is mainly a mixture of Oriental and African types, although there are some 

 peculiar forms. The only non-American alligator inhabits Central China. In 

 the Australian or tropical Pacific region, exclusive of New Zealand, we meet with 

 one group of land-tortoises, side-necked tortoises, and a crocodile ; while amongst 

 the lizards there are skinks, geckos, monitors, and the so-called agamoids; the 

 latter occurring in all the regions above mentioned, except Madagascar. Venomous 

 snakes here outnumber the harmless ones. The Tropical and South American 

 region is characterised by the presence of land and side-necked tortoises, to the 

 exclusion of soft-tortoises. Crocodiles and caimans are numerous (the latter being 

 characteristic) ; while of the abundant lizards the majority are iguanas, the true 

 lizards (Lacertidce) of the Old World being replaced by the teiias (Teiidce) ; 

 snakes are also numerous, among them being rattle-snakes and boas. In the 

 North American region there are no caimans, their place being taken by an 

 alligator ; while fresh-water S-necked tortoises, as well as soft-tortoises, replace the 

 side-necked tortoises of the southern half of the continent. The snapping tortoises 

 (Chelydriclce) are also mainly characteristic of this region, although one genus 

 ranges as far south as Ecuador. As regards its lizards and snakes, this region 

 presents the same relation to the preceding as is held by Euro- Asia to the Oriental 

 and African regions. Lastly, New Zealand stands apart from all other countries 

 in possessing the remarkable tuatera, in addition to which its only reptiles are 

 skinks and geckos. 



1 For the explanation of these and other names, the reader must refer to later chapters. 



