55 



gray colors, but some of the Old World forms are gorgeously 

 attired (Case T). The Crow-Shrikes of Australia are large forms 

 of this rather miscellaneous assemblage. 



The Vireos ( Vireoiiida) constitute a small family of distinctively 

 American birds, well represented in North America by our well- 

 known Vireos (see Case B, and Groups Nos. 9, 10, and 26), and 

 in tropical America by several allied genera (Case F). 



Fig. 18. American Water Ouzel and Nest. 



The Tree-Creepers [Certhiidce) number only about a dozen 

 species, half of which occur in Australia. New Guinea, and neigh- 

 boring islands, and the rest in North America, Europe, and the 

 northern parts of Asia. Only the northern forms have the tail 

 stiffened (see Cases B and T) ; in the Wall-Creeper and the Aus- 

 tralian Creepers (Case T) the tail is of the ordinary form. 



The Nuthatches {Sittidce) are a small family of climbing birds, 

 confined mostly to the temperate and colder portions of the 



