108 THE BIRDS OF MONGOLIA ETC. 



oa Lake Hanka it is also the scarcest species of the whole genus, passing 

 there only during migration early in April, and a few individuals stopping 

 till the end of that month on the Sungatch. 



278. Mergus albellus, L. Crahal lutock. 



We met with some birds at the end of March and beginning of April on 

 Dalai-nor, where it is commoner than the two preceding species. 



At Lake Hanka it is very numerous towards the end of March, but does 

 not form large flocks, as we usually saw small numbers only, which consisted 

 of Smews and Teals. They leave Lake Hanka early in April, and quite dis- 

 appear at the end of this month. 



279. PoDiCEPS CRisTATUS, L. N'wetz hohlatey. 



A single migrating bird was met with in April near the lower Dolon-nor ; 

 and some, I think, were noticed on Lake Urgan-nor, in the Hoang-ho valley. 

 To Lake Hanka it migrates at the end of March, and breeds in small numbers 

 on the solitary ponds. 



280. PODICEPS AURITUS, L. 



I think we saw this bird in April at Dalai-nor, and in the spring of the 

 following year in the Hoang-ho valley, but did not succeed in obtaining a 

 specimen. The present species is very rare in Mongolia, as is the pre- 

 ceding one. 



281. Larus niveus, Pall. Chaika sizaya. 



Larus canus, var. major, Middend. Sib. Reise, ii. part i. pi. xxiv. fig. 4. 



We found L. niveus in April in the Hoang-ho valley and in S.E. Mongolia, 



