CHAPTER VI. 



THE MALAGASY REGION. 



Limits Mammalian Fauna Relations of Madagascar to the Mainland. 



INCLUDED by Drs Sclater and Wallace within the Ethiopian 

 region, Madagascar and the adjacent groups of 

 islands were referred to a region apart by Dr Blan- 

 ford 1 ; this separation being justified not only by the mammalian 

 fauna, but likewise by many other groups of animals. To quote 

 Dr Wallace, this region "comprises, besides Madagascar, the 

 islands of Mauritius, Bourbon, and Rodriguez, the Seychelles, 

 and Comoro Islands. Madagascar itself is an island of the 

 first class, being a thousand miles long, and about two 

 hundred and fifty miles in average width. It lies parallel to 

 the coast of Africa, near the southern tropic, and is separated 

 by 230 miles of sea from the nearest part of the continent, 

 although a bank of soundings projecting from its western 

 coast reduces this distance to about 160 miles. Madagascar is a 

 mountainous island, and the greater part of the interior consists of 

 open elevated plateaus ; but between these and the coast there 

 intervene broad belts of luxuriant tropical forests." It is this 

 forest-district which forms the home of most of its peculiar fauna. 

 As regards geological structure, it [appears from the researches of 

 Messrs Cortese and Baron that, roughly speaking, a line drawn 

 from north to south so as to divide the island into two longitudinal 

 halves, gives an area of granitic and volcanic rocks on the right or 

 eastern side, and on the left or western side one of sedimentary 

 deposits, containing beds belonging to the Jurassic, Cretaceous, 

 Eocene and recent epochs. Blown sand occurs in abundance 



1 Appendix, No. 8, p. 76. 



