326 GEOGRAPHICAL DISTRIBUTION 



Ratitse (Rhea) which wander over its solitudes/ and the Impennes 

 (Penguin), which haunt its shores and those of the Falkland 

 Islands, besides the generalized Attagis, Chionis, and TItinocorys, the 

 Cariamidse, Palamedeidse, Phytotomidas, Pteroptoclddse, and other forms 

 which are wholly or nearly peculiar, while some of the most char- 

 acteristic Neotropical Families, Cserehidse, MniotiUidx, Tanagridm, 

 and Vireonidse, are but poorly represented or do not appear at all. 

 The Antillean being the only Subregion whose precise boundaries 

 can be definitely laid down, its Fauna, small as it is, is very in- 

 teresting. The unbroken chain of islands, to which in common 

 speech the name " West Indies " is wrongly limited, forms geo- 

 graphically a second connecting line between the two halves of the 

 American continent, and at once suggests a former communication 

 by land with Yucatan at one end and Venezuela at the other, to 

 say nothing of a possible junction with Florida. Yet omitting 

 other considerations,^ the peculiar forms of Bird-life manifested 

 throughout the chain shew that any such communication, if it ever 

 existed, must have been exceedingly remote in point of time ; for 

 narrow as are the channels between Cuba and Central America, 

 between the Bahamas and the south-western peninsula of North 

 America, and between Grenada and Tobago (the latter, as already 

 stated, belonging zoologically to South America) the Fauna of the 

 Antilles, instead of being a mixture of that of the almost con- 

 tiguous countries, differs much from all, and in some groups 

 exhibits a speciality which may be not unfitly compared with that 

 of Oceanic Islands. One might have expected here to find an 

 extremely varied animal population ; but no instance perhaps can 

 be cited to show more strildngly the difference between a con- 

 tinental and an insular Fauna ; since, making every allowance for 

 extinction since Europeans settled on the soil, jDOSsibly no area of 

 land so highly favoured by nature is so poorly furnished with the 

 higher forms of animal life, and here once more we have Birds 

 constituting the supreme Class — the scarcity of Mammals being 

 the normal effect of insularity. There is no Family of Birds 

 common to the Nearctic area and the Antillean Subregion without 

 occurring also in other parts of the Neotropical Region, a fact 

 which proves its affinity to the latter. Out of about 140 genera 

 found in the Subregion about 30 are peculiar to it, and these are all 

 Land-birds, being a ratio very nearly approaching that found in 

 Madagascar, but in no other subregional district ; and the dis- 

 tribution of some of the peculiar genera is very limited, for 19 out 

 of the 30 are confined each to a single island or nearly connected 



^ Rhea macrorhyncha, however, occupies an isolated station much further to 

 the north, in the province of Parahyba [Ibis, 1881, p. 361). 



2 For these see " Three Cruises of the ' Blake,' " by Alexander Agassiz, Bull. 

 Mus. Comp. Zool. Harvard Coll. xiv. xv. (Cambridge [Mass.] : 1888). 



