of the United States. 89 



running in pursuit of flying insects ; others alight on small 

 bushes, tops of trees, fences, &c. seldom on lower brauches. 

 Tail continually in motion. 



Hitherto considered as peculiar to the old continent. In 

 form of bill and activity in catching insects allied to Mus- 

 cicapa ; closely related to Sylvia, the American species par- 

 ticularly ; and comes also very near to that section of Turdus 

 called Saxicolae. 



143. Saxicola sialis, Nob. Blue ; beneath ferruginous ; belly 

 white. 



Female considerably duller. 



Young, dusky, spotted with white ; beneath dull whitish- 

 gray, varied with d sky ; wings and tail bluish. 



Blue bird, Sylvia sialis. Wils. Am. Orn. i. p. 56. pi. 3. fig. 

 3. adult male. Motacilla sialis, L. (Enanthe sialis, Vieill. 



Inhabits North America during spring, summer, and 

 autumn, as well as the West Indies, Mexico, and South Ame- 

 rica, where it winters : very common : a few resident in the 

 southern states. 



24. ANTHUS. 



Alauda, L. Gm. Lath. III. JMotacilla, Cuv. 



Anthus, Bechst. Temm. Vieill. Ranz. 



Bill straight, slender, subulate, destitute of bristles ; edges 

 somewhat inflexed in the middle ; upper mandible carinated 

 at base, then rounded, notched and declining at tip; lower 

 shorter, quite straight : nostrils basal, lateral, oval, half 

 closed by a membrane : tongue cartilaginous, bifid at tip. 

 Feet slender; tarsus longer than the middle toe; inner toe 

 free ; hind toe shortest, nail almost always long, straightish. 

 Wings moderate ; no spurious feather ; first, second and 

 third primaries longest ; secondaries emorginate at tip ; two 

 of the scapulars nearly equal to the longest primaries. 

 Tail elongated, emarginated. 



