14 SIGNIFICANCE OF LIMITED AREAS. [CH. I 



Greece as well as in India and Africa, where it is now alone 

 met with. And at an earlier period still it was found in 

 this country. The hippopotamus, now limited to Africa, 

 was once found in Madagascar, and probably the same 

 species in Europe. 



In such cases however the species in question are 

 generally also of generic, even of family, rank. The 

 remarkable lizard Hatteria, as already mentioned, is con- 

 fined to one or two islands off New Zealand ; this lizard, 

 as the fossil remains of its allies tell us, is the sole survivor 

 of the Rhynchocephalia, a race of Saurians found in the 

 Mesozoic rocks of this country. The Viverrine Carnivore 

 Cryptoprocta, found at present only in Madagascar, is held 

 by some to be the last surviving remnant of the extinct 

 Creodonta ; in any case it is generically distinct from any 

 other carnivorous animal. The same arguments may be 

 applied to the Thylacine of Tasmania, to the Aye- Aye 

 (Chiromys) of Madagascar, and to many other animals. 

 An apparently similar series of facts is therefore probably 

 to be explained in quite a different manner, an instance 

 of extremes meeting. The same mode of distribution 

 is indicative either of great antiquity or of extreme 

 modernity. 



A comparatively restricted range however may be also 

 due to incapacity for migration. The converse is perhaps 

 more obvious. Widely distributed animals are either 

 flying animals independent of barriers which impede the 

 purely terrestrial species, or possess some special facilities 

 for voluntary or involuntary translation from country to 

 country. An entirely arboreal creature cannot pass across 



