138 THE BOOK OF MIGRATORY BIRDS 



mantle and scapular feathers, contrasting with the other 

 dark plumage, are clear greyish-white, strongly marked 

 with wavy zigzag lines ; quills black, secondaries having 

 short black tips, but with the base white, forming a light 

 bar; lesser covers traversed by white lines; legs and feet 

 bluish-grey, webs darker. 



