626 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



of the crown and top of head cottony white, and the feathers decidedly 

 lanceolate in shape. 



Neck : The chin and throat ashy grey, with the shafts of the feathers 

 showing as distinct hair-like lines of black ; upper neck smoky blue-black, 

 concolor with the crown and the feathers with the same cottony white bases 

 and more or less pointed tips. 



Back : The entire back, including the upper tail-coverts, smoky blue- 

 black; the feathers of the interscapular region barely tipped with white 

 (the remaining signs of immaturity, as most adults are not decorated in 

 this way). The bases of all the feathers, including the upper tail-coverts, 

 cottony white. 



FIG. 315. 



Buteo melanoleucus. Tail from above ; reduced. 



Tail: The upper surface dull black, the feathers narrowly and rather 

 obsoletely tipped with ashy white ; the lower surface dull black, with a 

 decided brownish tinge and the light tips to the feathers much plainer and 

 better defined. 



Wings : The quills dull black, immaculate at the extremities and shaded 

 and barred on their outer webs with hoary ashy grey, barred, shaded and 

 vermiculated on their inner webs with a deeper shade of blue-grey ; on 

 the exposed surfaces of the inner secondaries a shade of dull brown suf- 



