II. 



Areas of specific distribution. — Generic distribution. — Distribution of families 

 and orders. — Conterminous and discontinuous areas of distribution. 



It is a fact of general observation that a given species of animal 

 is so restricted in its range as to entitle the geographical area prinoi- 

 palljf occupied by it to be considered as its home. This home may 

 be limited in its extent to a very narrowly circumscribed area, possibly 

 not embracing more than a few square miles, or even less, or it may 

 spread out to dimensions coextensive (or nearly so) with the conti- 

 nental boundaries ; or, finally, it may comprise considerable portions 

 of two or more continental areas combined. As examples of animals 

 having a very restricted geographical distribution may be cited the 

 Pyrenean water-mole (Myogale Pyrenaica), a small insectivore found 

 only in a very few localities of the northern valleys of the Pyrenees, 

 and a species of buschbok (antelope, Cephalophus Natalensis), 

 whose habitat is the region about Port Natal, South Africa. Arc- 

 tomys caudata, one of the Asiatic marmots, is confined to the ele- 

 vated valley of Gombur, in India, and to heights exceeding 13,000 

 feet. Of birds, whose powers for self-distribution are much more 

 fully developed than among mammals, we- have equally pointed 

 examples of localisation. The brown-and- white cactus-wren (Cam- 

 pylorhynchus albibrunneus) is confined exclusively to the Isthmus 

 of Panama, where its range is also somewhat limited ; the Bornean 

 yellow-bulbul (Otocampsa montis) has only been met with on the 

 peak of Kina-Balu, in Borneo ; and the red bird-of-paradise (Para- 

 disea rubra) only within the narrow limits of the island of Waigiou, 

 lying to the northwest of New Guinea. The most remarkable in- 

 stances of localisation are probably afforded by the humming-birds, 

 several species of which would seem to be restricted respectively to 

 the volcanic peaks of Chimborazo and Pichincha, in the equatorial 



