THE BIRDS 



NORTH AND MIDDLE AMERICA, 



By Robert Ridgwat, 



Curator, Division of Birds. 



Part III. 



Family MOTACILLID^. 



THE WAGTAILS AOT) PIPITS. 



Terrestrial nine-primaried acutiplantar Oscines, with the tertials 

 conspicuously elongated (often reaching nearly or quite to tip of 

 longest primaries), the bill slender and notched, the tarsi long and 

 slender, and the hind claw usually conspicuously elongated. 



Bill slender-conoid, decidedly shorter than head, its depth at nostril 

 equal to less than half the distance from nostril to tip of maxilla, its 

 width at same point slightly greater; culmen shorter than middle toe 

 without claw, slightlj'^ curved terminally, often depressed subbasally; 

 maxillary tomium obviously, but not conspicuously, notched subter- 

 minally. Rictal bristles obvious, but only two conspicuously devel- 

 oped. Nostril exposed, longitudinally ovate or subcuneate, overhung 

 by a broad membraneous operculum. Wing rather long and pointed, 

 but tip subtruncate, the four to five outermost primaries longest and 

 subequal; outer webs of eighth, seventh, and sixth — rarely also the 

 fifth — primaries slightly sinuated subterminally; shorter (innermost) 

 primaries and secondaries emarginated at tips; innermost secondaries 

 (tertials) conspicuously elongated, often nearly equally, sometimes 

 exceeding, the longest primaries. Tail variable in relative length, but 

 never conspicuously shorter than wing, usually nearly as long, some- 

 times longer, the tip even, slightly emarginate, double-emarginate, 

 rounded, or double-rounded, the rectrices rather narrow, usually 

 10384— VOL 3—03 1 l 



