Family	MACGILLIVRAY'S GROUND-WARBLER. [MacGillivray's Warbler (see also Mourning Ground-Warbler).]
Genus	TRICHAS MACGILLIVRAYI, Aud. [Oporornis tolmiei.]

When I first saw the specimens of this bird, which had been transmitted by Mr. TOWNSEND to the Academy of Natural Sciences of Philadelphia, I considered them as identical with Sylvia Philadelphia of WILSON; but on subsequently comparing them with a number of individuals of the latter species, procured by my friend EDWARD HARRIS, Esq. in our Middle and Eastern Districts, I found differences sufficient to indicate their being specifically distinct. In consequence of which I have dedicated this pretty little bird to my excellent friend WILLIAM MACGILLIVRAY, Esq. and feel much pleasure in introducing it to the notice of the ornithological world, under a name which I trust will endure as long as the species itself.

Mr. TOWNSEND, who found it on the banks of the Columbia, states that it is mostly solitary and extremely wary, keeping chiefly in the most impenetrable thickets, and gliding through them in a cautious and suspicious manner. It may, however, sometimes be seen towards mid-day perched upon a dead twig over its favourite places of concealment, and at such times warbles a very sprightly and pleasant little song, raising its head until its bill is almost vertical, swelling its throat in the manner of its relatives."

Mr. NUTTALL has also favoured me with the following interesting account of it.--"This species is one of the most common summer residents of the woods and plains of the Columbia, appearing early in May, and remaining until the approach of winter. After the manner of the Maryland Yellow-throat, it keeps near the ground in low bushes, where it gleans its subsistence. When surprised or closely observed, it is shy and jealous, immediately skulking off, and sometimes uttering a loud snapping clink. Its note has occasionally the hurried rattling sound of Turdus aurocapillus, resembling t'tsh t'tsh ttsh tsheetee, alternately into tsh tsh tsh teet shee. Another male, on the skirts of a thicket, called out at short intervals vish vishtyu, changing to vit vit vit vityu and vit vit vityu, sometimes, when approached, dropping his voice, and abbreviating his song. Another had a call of visht visht, visht e visht t'shew, and visht visht vishteshew or vititshee. On the 12th of June, a nest of this species was brought to me, containing two young birds nearly quite fledged, in the garb of the mother, pale yellow beneath, and brightish yellow-olive above. The nest was chiefly made of stripes of the inner scaly bark of probably the white cedar, Thuya occidentalis, lined with slender wiry stalks of dry weeds, and concealed near the ground in the dead mossy limbs of a fallen oak, and further partly hidden by a long tuft of usnea. It was less artificial than the nest of the Yellow-throat, but of the same general appearance, and concealed in a similar situation, probably in a thicket near the ground. On returning the nest to the place it had been taken from, I had almost immediately the satisfaction of seeing the anxious parents come to feed their charge, and for some days they shewed great anxiety on being approached."

"This," says my friend Mr. HARRIS, "is the Warbler that so closely resembles the S. Philadelphia. Mr. TOWNSEND has brought in more specimens, which agree with the others in the very distinctive mark of the white eyelids, with dark spots from the base of the bill to the eyes, and also dark on the front at the root of the upper mandible. I cannot but think it entirely distinct."

This species, as has already been observed, is very intimately allied in form, proportions, colours, and habits with that described by Wilson under the name of "Mourning Warbler, Sylvia Philadelphia." His account of the latter is as follows:--"The bird from which the figure in the plate was taken, was shot in the early part of June, on the border of a marsh, within a few miles of Philadelphia. It was flitting from one low bush to another, very busy in search of insects, and had a sprightly and pleasant warbling song, the novelty of which first attracted my attention. I have traversed the same and many such places, every spring and autumn since, in expectation of again meeting with some individual of the species, but without success. I have, however, the satisfaction to say, that the drawing was done with the greatest attention to peculiarity of form, markings, and tint of plumage; and the figure on the plate is a good resemblance to the original."

MACGILLIVRAY'S WARBLER, Sylvia Macgillivrayi, Aud. Orn. Biog., vol. v.p. 75.

Wings rather short, the second quill longest, the fourth longer than the first, the tail long, considerably rounded, its feathers rounded; tarsus longer than the middle toe and claw. Male olive-green above; the head, hind part, and sides of the neck bluish-grey; the fore neck and part of the breast greyish-black, lunulated with greyish-white; a black loral band; a conspicuous white spot on each eyelid; the lower parts bright yellow. Female olive-green above, yellow beneath, the sides of the neck and a band across the breast ash-grey.

Male, 5 1/4, 6 1/2. Female, 5, wing 2 (4 1/2)/12.

Columbia river. Common.