192 THE BIRDS OF MONGOLIA ETC. 



note. In Kan-su it finds its northern limit, but was observed by us also at 

 Koko-nor and in Northern Tibet. Our specimens have not such a deep 

 violet colour on the underparts of the body as is the case with birds from 

 Turkestan. 



93. MOTACILLA LUZONIENSIS, ScOp. 



Motacilla alba, var. paradoxa, Schrenck^ Reisen und Forschungen im Amur-Lande, i. pi. xi. 

 fig. 2. 



Rare in Eastern Mongolia and Ala-shan, but common in Kan-su, where 

 it sometimes ascends to the alpine regions. I cannot detect any difference 

 between Schrenck's specimens and the birds brought home by me, which 

 latter were killed in spring and have black and blackish-grey backs. 



In Ussuri country it is extremely common, and arrives at Lake Hanka 

 at the end of March, leaving again for the south about the beginning of 

 October. 



94. Motacilla dukhunensis, Sykes. 



Motacilla dukhunensis, Gould^ Birds of Asia_, part xiii. pi. 



We met with this species only at Koko-nor, where the first migrants 

 arrived on the 23rd of March ; and the two males secured at that time had 

 not got the full colour on the throat, which is almost quite white. Probably 

 the species breeds at Koko-nor, and possibly ranges as far as Kan-su. It 

 does not appear to difi^er from the preceding and following ones in its habits ; 

 and these, again, are in this respect exactly similar to M, alba. 



95. Motacilla ocularis, Swinh. 



Motacilla alha, var. lugens, Schrenck_, Reisen und Forschungen im Amur-Lande, i. p. 338. 



Abundant throughout Mongolia, but does not occur either in Kan-su or 

 about Koko-nor. Breeds in the neighbourhood of brooks and rivulets, and 



