Avifauna of Central America. 767 



thau 12 are North American — of these, six winter iu 

 Mexico and Central America, and one in Brazil. 



So far as the facts of distribution are concerned, the 

 recognition of the three genera Merula, Tardus, and H'/lu- 

 cichla seems to be justified. But if judged by the standai'd 

 of anatomy, the only satisfactory basis for systematic work, 

 the genera Merula and Hylocichla should be merged with 

 Turdus, which might conveniently be subdivided into thrte 

 sections. 



The absence of the Ruticillinae and Saxicolinaj from the 

 Central and South American Regions is noteworthy. These 

 groups are, indeed, unknown throughout the American con- 

 tinent, save only iu the case of the Saxicolinje, wdiich are 

 represented by two species of Wheatear. One of these 

 {(Enanthe cenanthe) breeds all over Europe, as well as in 

 northern and central Asia, whence it seems to have made its 

 way into Alaska. The other is the Greenland Wheatear 

 (CEnanihe leucorrhoa), a bird of passage in Great Britain, 

 breeding in Greenland and Labrador. Thus this genus 

 enters America from opposite sides of the continent, but its 

 range there is strictly confined to the high north, though 

 casual specimens may stray as far south as Louisiana and 

 Colorado. 



Inasmuch as theTurdida? and Sylviid?e are nearly related, 

 it seems curious that the latter should be represented in the 

 New World only by four species of the genus Regulus. But 

 such is the case. Guatemala forms their southernmost 

 limit ; but only two species, as a matter of fact, pass into 

 and beyond Mexico — 7?.ifa/r«/>a ranges from North America 

 into Mexico, and R. calendula fiom Repulse Bay and Green- 

 land in the north to Guatemala. 



Of the five genera comprising the Sialiinse, four are 

 peculiar to the American continent. One, Zeledonia *, is 

 found only in Central America ; Catharus occurs both iu 

 Central and South America ; Stalia, a genus containing 



* Pycraft, W. P., " On the Systematic Position oi Zeledonia coronata, 

 with some Observatious on the Position of the Turdidas," Ibis, 1905, 

 p.l. 



