420 CHARACTERS OF TACHYCINETA THALASSINA 



through Mexico to Guatemala at least. Breeds in its United States and 

 British American range and in higher portions of Mexico. Winters beyond 

 the United States. 



Ch. SP. — ^ 9 Violaceoviridis, pileo magis purpurescenfe, 

 torque cervicali et tectricihus caudalihus superioribus purpurea- 

 violaceis ; alls cauduque violaceofuscis ; infra sericeo-alba. 



$ , adult : Entire under parts, including the sides of the head to just above 

 the eyes, and an enlarged fluffy tuft on the flanks tending to join its fellow 

 over the rump, pure silky white. Upper parts rich, soft, velvety-green, 

 mixed with a little violet-purple ; the crown of the head similar, but rather 

 greenish-brown, with a purplish tinge. Cervical region, in some cases a 

 well-defined though narrow cervical collar, and the upper tail-coverts violet- 

 purple. These rich colors without gloss or sheen ; wings and tail blackish, 

 with violet and purplish gloss. Bill black ; feet brownish-black, small ; 

 iris brown; mouth pale yellow. Length, 4^5 inches; extent, llw-12^; wing, 

 4i; tail, 2, lightly forked ; bill, ^J^; tarsus, f. 



The 9 ) Ji-Dtl immature birds in general, differ simply in the less purity and 

 intensity of the colors of the upper parts. In the very highest jilumaged 

 specimens, the back is nearly pure green, the cervical collar distinct, and 

 the several contrasts of crown, collar, back, and upper tail-coverts are 

 strong; in general, the back has a brownish-purple shade, more like that of 

 the crown. 



Very young birds, just from the nest, are exactly like those of T. hicolor, 

 though smaller, being dark mouse-gray above and white below. But traces 

 at least of the special tints speedily appear. Young or perhaps autumnal 

 birds usually have the inner secondaries white-tipped, as in T. hieolor. 



MR. BULLOCK appears to have discovered this bird in 

 Mexico prior to 1827, when Swaiusou published a syn- 

 opsis of the collection made by the Bullocks, sr. and jr., in the 

 Philosophical Magazine — an article famous for the number of 

 its new genera and species, among them many now well known, 

 the Swainsonian names of which are very familiar to us. 

 Among the genera are Setophaga, Seiurus, Sialia, Si/lvicolaj 

 Ammodramus^ Chondesies, Dolichonyx, Agelccus (originally writ- 

 ten Agelaus), Guiraca. For all these new genera, and others 

 (none being here characterized), reference is made to the then 

 still unpublished no. 10 of vol. iii. of the Zoological Journal, 

 April-Sept., 1827, and the latter is generally cited as the source 

 of the names ; but this article in the Phil. Mag. has actual 

 priority by a short time. The real student of ornithology will 

 find it necessary, sooner or later, to consult this paper, and I 

 advise all who have not done so to lay hands on the book, in- 

 stead of stealing their quotations from Bd. BNA., as most have 

 done for twenty years. 



