I 72 Allex, Origin and Distribution of N. A. Birds. \\\n\ 



Auk 



1 



both continents, being tropical rather than North American, and 

 nearly the same may be said of Setophaga. Granatellus, Car- 

 dellina and Ergaticus are Mexican and Central American, the 

 two latter barely reaching our Mexican frontier. Dendroica is 

 represented by about forty species, of which twenty-four, or 

 about 60 per cent., may be considered as distinctively North 

 American, while eleven, or So per cent., of the remaining species 

 are West Indian ; two are Central American and one occurs in 

 the Galapagos Islands. Thus, in general terms, about one fourth 

 of the species are West Indian and three fourths North American. 

 The remaining eight genera are strictly North American, while 

 three of them, Helmitherus, Helinaia and Protonotaria, are 

 restricted to the eastern half of the United States, as is also 

 Compsotlrfypis, so far as its United States distribution is con- 

 cerned. Mniotilta is also eastern. 



The large and widely dispersed Old World family Motacillidie 

 has only two genera in North America — Budytes, barely reach- 

 ing Alaska, and the nearly cosmopolitan genus Anthus. 



Cinclus is a mountain type, common to most of the higher 

 mountain ranges of America and Eurasia. 



The Troglodytidae is almost exclusively an American family, 

 represented in Eurasia by the subgenera Artorthura and Ela- 

 chura. A few East-Indian genera are sometimes placed here, as 

 Sphenocichla, Pneopyga, etc., but I think erroneously. The 

 metropolis of the true Wrens is tropical America, where are 

 found more than nine tenths ofall the species of the group. The 

 genera Cistothorus, Thryothorjis^ and Campylorhynchus extend 

 into the warmer parts of the United States. Salpinctes and 

 Catherpes are peculiar forms of the West and Southwest, of 

 probably Mexican origin. 



The subfamily Miminse, of late associated with the Wrens, is 

 exclusively American, and four out of the five North American 

 genera doubtless originated near where they are now found. One 

 of them, Galeoscoptes, is essentially eastern and one, Oroscoptes, 

 is western. Mimus is tropical, with a single outlying species 

 in North America. 



Of the Paridaa, Sitta and Parus are found throughout the 

 greater part of the northern hemisphere ; Chamcea, Psaltri- 

 parus, and Auriparus are mainly limited to the northern border 

 of Mexico and the adjoining tier of States to the northward, a 



