I cannot agree with Mr. Newton in considering the Gerfalcons of the interior of Arctic America as identical with the Iceland form, though that distinguished ornithologist considers them so in his paper in the Proceedings of the Philadelphia Academy for July, 1871, basing his conclusion upon the specimens from which the above descriptions were taken, which had been sent over to England for comparison. I have never yet seen a specimen of islandicus which could not be distinguished, by the characters given in my synopsis, from these examples, while they can be separated from that race by the characters which Mr. Newton himself gives, in his diagnostic table in the paper above cited, for distinguishing the adults of islandicus and gyrfalco.
The var. sacer is evidently separable from both islandicus and gyrfalco, and about as much related to one as to the other; combining the size and proportions of the former with the colors of the latter, while in the wide amount of individual variation of plumage its lighter extreme approaches one, while its darkest phase approximates as closely to the average plumage of the other.
LIST OF SPECIMENS EXAMINED.
National Museum, 6.
| Sex. | Wing. | Tail. | Culmen. | Tarsus. | Middle Toe. | Specimens. |
|---|---|---|---|---|---|---|
| ♂ | 13.35–14.25 | 8.50–9.00 | .86–.93 | 2.15–2.40 | 1.80–1.95 | 3 |
| ♀ | 15.50–16.00 | 10.00–10.50 | 1.00–.00 | 2.35–2.55 | 2.00–2.15 | 3 |
Var. labradora, Audubon.
BLACK GERFALCON.
Falco labradora, Aud. B. Am. pl. cxcvi, 1831.
Sp. Char. Adult (♀ breeding plumage? 30,375, Rigolet, Labrador; Mr. Conolly). Ground-color of the plumage uniform, very deep, clear, dark plumbeous-brown, continuously uniform above; larger scapulars, secondaries, secondary coverts, and primaries more dilute along edges, however, the tint palest and broadest terminally. Tail perfectly uniform, except at the end; the tip being narrowly whitish, and about half an inch anterior to this, a transverse series of hidden irregular transverse creamy-white spots. The head (except beneath) is unvariegated. Beneath, the dark tint inclines more to blackish clove-brown, more dilute on the tibiæ; feathers edged laterally with white, this prevailing on the throat, but everywhere else far less than the dusky in amount; on the tibiæ and lower tail-coverts the white is in the form of irregular spots. Anal region unvariegated; lining of the wing with circular spots of white along the outer webs of the feathers. Under surface of primaries with plumbeous prevalent, but this crossed with mottlings of whitish, forming transverse bars; but terminally and basally they become confused or lost. Wing-formula, 2, 3–1, 4. Wing, 16.20; tail, 9.50; tarsus, 2.00–.90; middle toe, 2.05; inner, 1.50; outer, 1.50; posterior, .90.
Hab. Labrador; south and westward in winter, and shores of Hudson Bay.
Nos. 17,063 (♀, Quebec, W. Cooper) and 34,960 (♀, Fort Nescopec, Labrador) differ from the preceding in having ten small narrow transverse spots of reddish-white on the tail-feathers, forming as many indistinct bands; these spots touch neither the shaft nor the edge of the feather, and are almost concealed, unless the tail is spread; on the latter specimen they are very obsolete, the subterminal one only being distinct, as in the specimen selected for description. The upper tail-coverts also show faintly indicated spots, and the former specimen has the wing-coverts with very narrow irregular spots on the edge of the feathers. In this specimen there is also one feather in the scapulars which has broader white edges; it also has the white below about equal to the black in amount; the anal region, however, in all, is unvaried blackish, and the transverse oblique bands on the lower tail-coverts are a constant feature.