68 Mr. N. A. Severtzow on the 



migration. It was obtained near the source of the Tchon-su, 

 in the river-system of Lake Kara-kul, in August, at a height 

 of 14,000 feet. 



-f-57. Cyanecula suecica (Limi.). 



The Arctic Blue-throated Robin is common on the Alai 

 in July and in August, near the sources of the Kashgar-Darya, 

 and throughout the Pamir, where it was obtained moulting. 

 It probably breeds there. 



58. RUTICILLA RUFIVENTRIS, Vicill. 



The Indian Redstart is an autumn visitant in the Pamir, 

 arriving in August and disappearing in October. 



59. RUTICILLA ERYTHROGASTRA, Glildcnst. 



Giildenstadt's Redstart is found on passage through the 

 Pamir in September and October ; the earliest arrivals of this 

 species are seen in the first half of September. 



60. MoNTicoLA SAXATiLis (Linn.). 



The Rock-Thrush passes through the Pamir in August. It 

 is not common ; but perhaps it may breed there. 



61. MoNTicoLA CYANUS (Linn.). 



The Blue Rock-Thrush was seen during migration on the 

 13th September near Ak-su. 



62. Saxicola isabellina, Riipp. 



The Isabelline Chat is very common in the Alai and the 

 Pamir, where it breeds. It ascends as high as the Leuco- 

 *^k^e in the upper alpine zone. The young birds on the Alai 

 retain their nestling-plumage till the end of July, and on the 

 Pamir even till the end of August — a conclusive proof that this 

 species breeds there ; the higher they live the later they retain 

 it. This species appears quite to replace S. cenanthe in the 

 Alai and the Pamir. In the narrow-ridged chains of the 

 Tian-shan system S. oenanthe ascends into the alpine region 

 far above S. isabellina, which there only reaches the treeless 

 outskirts of this region, whereas in the Pamir it ascends to a 

 far greater height. Specimens of Saxicola isabellina from the 

 Pamir do not differ from those inhabiting the hottest steppes 



