264 MOTACILLIDyE. 



KEY TO THE FAMILIES. 



a. Back of the tarsus plain ; wing of only nine 



primaries, bastard primary absent .... Motacillida. 



b. Back of tarsus scaled ; wing nearly always 



with a distinct bastard primary Alaudidce. 



Family VII. MOTACILLIDJE. 



Bill shorter than the head. Wing with only nine primaries, no bastard 

 primary, the three outer primaries nearly equal and the longest ; larger 

 secondaries reach almost or quite to tip of wing. Tail nearly square, of 

 twelve feathers. Tarsi rather long and slender, bilaminated behind and in 

 front somewhat scutellated. Generally the plumage is alike in both sexes 

 and very similar in the nestling ; but sometimes the colouring is considerably 

 altered by the autumn and spring moults. 



They frequent the ground mostly, especially near water, and feed almost 

 entirely upon insects. About thirty-two species are known to occur in the 

 Ethiopian region, and of these a third frequent it only during migration. 



KEY TO THE GENERA AND SUB-GENERA. 



a. Plumage of upper parts uniform and never 



brown in adults ; profile of culmen nearly 

 straight from the base to the tip, and about 

 equal in length to the outer toe with claw ; 



feet dark Motacilla. t-L^~ 



a 1 . Tail longer than the wing ; hind claw 



shorter than the hind toe. 

 a 2 . Under tail-coverts white, subgen. . . . Motacilla, Linn. 1766. 

 b 2 . Under tail-coverts bright yellow, subgen. Calobates, Kaup. 1829. 

 b 1 . Tail shorter than the wing; hind claw 



longer than the hind toe ; lower throat, 



breast and under tail-coverts uniform 



bright yellow in full plumage, subgen. . . Budytes, Cuv. 1817. 



b. Plumage of upper parts brown and lark-like ; 



profile of culmen curved from the centre to 

 the tip ; feet pale. 



