74 



distinct from the Motacilla alba of Linnaeus. He proposed for it the 

 name of M. Yarrellii, and observed, that it might be easily distin- 

 guished from the Continental one, -vvith ^hich it had hitherto been 

 confounded, by an attention to the folio wing characters. 



The pied wagtail of England {M. Yarrellii) is somewhat more ro- 

 bust in form, and in its fuU summer dress has the whole of the head, 

 chest, and back of a fuU, deep, jet black ; while in M. alba, at the 

 šame period, the throat and head alone are of this colour, the back 

 and the ręst of the upper surface being of a light ash-grey. In winter 

 the two species more nearly assimilate in their colouring ; and this 

 circumstance has doubtless been the cause of their being hitherto 

 considered identical ; the black back of M. Yarrellii being grey at 

 this season, although never so light as in M. alba. An additional 

 evidence of their being distinct (but 'vvhich has doubtless contributed 

 to the confusion), is, that the female of M. Yarrellii never has the 

 back black, as in the malė ; this part, even in summer, being dark 

 grey ; in which respect it closely resembles the other species. 



