( 57 ) 



BLACK-THROATED GREY WARBLER. 



Sylvia nigrescens, Townsend. 



PLATE CCCXCV. Male. 



This is another of the interesting species discovered and named 

 by Dr Townsend, who informs me that it is called " Ah Kah a quaV 

 by the Chinook Indians ; that it is abundant in the forests of the Co- 

 lumbia, where it breeds and remains until winter ; and that the nest, 

 formed externally of fibrous green moss, is generally placed on the 

 upper branches of the oak, suspended between two small twigs. Mr 

 Nuttall's notice respecting it is as follows : — " This curious species, 

 so much resembling Sylvia striata, was seen to arrive early in May ; 

 and from its song more regularly delivered at intervals, in the tops of 

 deciduous-leaved trees, we have little doubt but that they breed in the 

 forests of the Columbia. On the 23d of May I had the satisfaction of 

 barkening to the delicate but monotonous song of this bird, as he bu- 

 sily and intently searched every leafy bough and expanding bud for 

 larvae and insects in a spreading oak, from whence he delivered his 

 solitary note. Sometimes he remained a minute or two stationary, 

 but more generally continued his quest for prey. His song, at short 

 and regular intervals, seemed like H sliee H shay t shaitshee, varying the 

 feeble sound very little, and with the concluding note somewhat slen- 

 derly and plaintively raised." 



For the drawing of the plant represented in this plate, and no- 

 ticed in the preceding page, I am indebted to my much esteemed friend 

 Miss Martin. 



Sylvia nighescens, Black-throated Grey Warbleb, Townsend, Joum.of Acad, 

 of Nat. Sciences of Philadelphia, vol. vii. p. 191. 



Adult Male. Plate CCCXCV. Figs. 5, 6. 



Bill shortish, straight, rather strong, tapering, compressed toward 

 the end ; upper mandible with the dorsal outline convex and declinate 

 toward the acute tip, the sides convex, the edges sharp and overlap- 

 ping, without notch ; lower mandible with the angle short and rounded, 

 the dorsal line very slightly convex, the edges a little inclinate, the 



