2 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



tapering terminally, but never (except sometimes middle pair) pointed 

 at tip. Tarsus slender, of variable relative length, but always much 

 longer than bill, the acrotarsium usually more or less distinctly 

 scutellate, sometimes fused except on lower portion; toes slender, the 

 middle one distinctly longer than the lateral toes, of which the inner is 

 sometimes slightly longer than the outer; hallux about equal in length 

 to lateral toes or slightly longer, but stouter; outer toe with basal 

 phalanx adherent to middle toe, but inner toe almost entirely free; 

 claws slender, variable in relative length, that of the hallux (except in 

 genus Jfofacilla) elongated and but slightly arched, equal to or exceed- 

 ing the digit in length. 



The Motacillidse are birds of terrestrial habits, walking or running 

 gracefully on the ground, instead of hopping; and feed upon insects. 

 The wagtails are usually of j^ied (black, gray, and white) plumage, but 

 sometimes partially bright yellow- — always unstreaked. The pipits 

 are of streaked plumage, with brownish or tawny tints prevailing, in 

 which respect they present a remarkable resemblance to the larks 

 (family Alaudidae), as they do also in their habits and the character of 

 their nests and eggs. 



The family is most developed in the Eastern Hemisphere, to which 

 the wagtails are restricted; America possessing, as peculiar species, 

 only the pipits, represented b}^ abovit eight species, belonging to two 

 or three genera or subgenera. 



KEY TO THE GENERA OF MOTACILLID.E. 



a. Plumage without streaks; tail longer (nearly equal towing, sometimes longer); 



under parts plain white or yellow, with or without black on chest and throat. 



{MotacUlx. ) 



h. Claw of hallux shorter than the digit, strongly curved; under parts of body 



white, or if yellow the throat or a jugular crescent black; back gray or black; 



no yellow on head Motacilla (p. 2) 



bb. Claw of hallux longer than the digit, slightly curved; under parts yellow, 

 without black on throat or chest; back olive-green, or if gray or black the 



whole head yellow Budytes (p. 7) 



cm. Plumage more or less streaked; tail shorter (decidedly shorter than wing) ; under 

 parts neither pure white nor yellow (more or less brownish or buffy), more or 

 less streaked, at least on sides, and without black on chest or throat, except in 

 form of streaks. {Antheie. ) Antlnis« (p. 10) 



Genus MOTACILLA Linnaeus. 



Motacilla Linnaeus, Syst. Nat., ed. 10, i, IT.'SS, 1S4. (Type, by elimination, M. 



alba Linnfeus. ) 

 Calohates'Kw.v, Naturl. 8yst., 1829, 33. (Type, Motacilla nielanope ^aW&s.) 

 Pallenura Bonaparte, Consp. Av., i, 18-50, 2.50. (Type, Motacilla melanope 



Pallas.) 



Motacillidge with the hind claw shorter than its digit and strongly 

 curved; scutella of acrotarsium often indistinct, sometimes fused. 



« I must confess mv inability to .satisfactorily subdivide the genus Anthuii. 



