160 THE BIHDS OF MONGOLIA ETC. 



We did not observe when they leave MongoHa in their autumnal migration, 

 and can only state that in Halha the last specim^ens we saw were flying 

 southwards at the commencement of August. It does not occur in Ussuri 

 country, but breeds numerously on the rocky shores of the Amur river. 



29. Chjetura^ caudacuta. Lath. 



Chmtura caudacuta, Gould^ Birds of Australia^ ii. pi. x. 



We met wdth a few specimens on their autum^nal migration in S.E. 

 Mongolia at the northern bend of the Hoang-ho. It does not occur in Kan-su ; 

 but the English naturahsts state that it breeds in the highest rocks of the 

 Himalayas, near the perpetual-snow region. It goes as far north as Jakutsk ; 

 and a specimen obtained there is now in the Irkutsk Museum. It is tolerably 

 common in Ussuri country, and breeds in the cliffs on the shores of rivers 

 and in the hollow trees. It seemed to me to be commonest on the forest- hills 

 about Lake Hanka. Usually several pairs breed close to each other; and 

 during the season of propagation (i. e, in May) the males, like our Swifts, 

 chase the females on wing, describing all sorts of circles in the air, uttering 

 a weak note which is more like that of our Swallow than our Swift. 



In Ussuri country Chcetura caudacuta arrives at the end of April, and in 

 Mongolia a week or two later. The migrating ones do not form compact 

 flocks, but fly at small distances from each other and very close to the ground. 

 We saw them leave Mongolia in the autumn in this way. Their departure 

 from the southern parts of Ussuri occurred in the end of August, some of 

 them remaining, however, as late as the beginning of September, The prin- 

 cipal migration took place on the 9th of September, when we saw an almost 

 uninterrupted flock of them passing above our heads for almost a whole day. 

 They were migrating in company with C, pacificus, 



30. HiRUNDO GUTTURALIS, Scop. 



This eastern representative of our Swallow is met with throughout 



