456 AZURE WARBLER. 



moderate thickness, the lower muscle thin, the epithelium dense, red- 

 dish-brown, and longitudinally rugous when not filled ; the intestine 

 rather short and of moderate width ; two very small cceca ; the rectum 

 gradually enlarged. The trachea is composed of from 60 to 80 rings, 

 flattened, somewhat tapering ; the bronchi of ordinary size, of from 12 

 to 15 rings ; there are cleido-tracheal muscles, lateral muscles, sterno- 

 tracheal, and four pairs of inferior laryngeal. 



AZURE WARBLER. Sylvia azure a, Stephens. 



PLATE XL VIII. Vol. I. p. 235. Adult. 



BLUE-GREEN WARBLER. Sylvia rara, Wils. 



PLATE XLIX. Vol. I. p. 258. Young. 



In the course of my late joiu"ney to the Texas I found the Azure 

 Warbler entering the United States from Mexico, early in AprU, when 

 it was in perfect plumage. On an island on which we landed, about 

 an hour before sunset, some hundreds had stopped to pass the night, 

 the appearance of the weather being threatening. My friend Edward 

 Harris and my son shot a number of them. Next day few were seen, 

 and in about a week they had all proceeded eastward. The whole 

 breadth of oiu" country, from the Atlantic shores to those of the Pacific, 

 is visited by this bird, which was found along the Columbia River at 

 Fort Vancouver by Dr Townsend. The most eastern point at which 

 I have known it to be procured is the neighbourhood of Pictou in No- 

 va Scotia. It is not mentioned by Dr Richardson. 



As to the Syhia rara, my doubts regarding its specific distinction 

 are as great as ever, especially as no one has found its nest. I men- 

 tioned my suspicions to the Prince of Mdsignano, who has placed it in 

 his list as the young of Syhia azurea. 



