_Juv. first plumage_ (♀, 56,053, Greenland; Schlüter Coll.). All the markings are longitudinal, instead of directly the reverse. The upper parts have longitudinal tear-shaped stripes, a medial one on each feather; they are sparse, however, on the wings; the rump has narrow shaft-lines of dusky. The tail and upper coverts are immaculate, but the shafts of all the feathers are nearly pure black. The bars on the primaries are found only immediately next the dusky terminal space. The streaks beneath are not very numerous, and are found only on the breast, upper part of abdomen, and on the sides; the nape and sides of the neck are, however, thickly streaked. (No. 17,966, ♀, Moose Factory, Hudson Bay Territory.) In character of markings resembling the last, but the stripes are fainter and narrower; they are also less numerous. On the under parts they are wanting. Unfortunately, the tail of this specimen, which is the only North American one in the collection, is missing. In all specimens the anal region and lower tail-coverts are immaculate. HAB. Greenland, and continent of North America, north of Hudson Bay (breeding in latter region). Of irregular occurrence in winter throughout the circumpolar regions; Ural Mountains (EVERSMAN); Behring’s Strait (BANNISTER). LIST OF SPECIMENS EXAMINED. National Museum, 7; Boston Society, 2; Philadelphia Academy, 3; New York Museum, 6; collection of R. Ridgway, 1. Total, 19. _Measurements._ +----+-----------+-----------+---------+---------+-----------+----------+ |Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.| +----+-----------+-----------+---------+---------+-----------+----------+ | ♂ |14.40–14.75| 9.70–00.00| .90–0.00|2.15–2.45| 1.95–2.00| 3 | +----+-----------+-----------+---------+---------+-----------+----------+ | ♀ |15.75–16.25|10.00–11.00| .98–1.00|2.20–2.50| 2.05–2.15| 6 | +----+-----------+-----------+---------+---------+-----------+----------+ Var. islandicus, SABINE. ICELAND GERFALCON. _Accipiter falco islandicus_, BRISS. Orn. I, 336, 1763. _Falco islandicus_, SAB. Linn. Trans. XII, 528, 1818.—TEMM. Man. Orn. pt. x; 17, pt. iii, p. 9; Tab. Meth. p. 2, 1836.—FABER, Prod. Island. Orn. 1822, p. 2; Isis, 1827, 62.—RICH. & SWAINS. F. B. A. II, 27, 1831.—HOY, Mag. Nat. Hist. Ser. 1, VI, 107.—HANCOCK, Ann. Nat. Hist. II, 247; Rev. Zoöl. 1839, 123.—BONAP. Consp. Av. p. 24.—STRICKL. Orn. Syn. I, 77, 1855.—CASSIN, Birds N. Am. 1858, 13. _Hierofalco islandicus_, GRAY, Gen. B. p. 3 (ed. 2, p. 4), 1844; Hand List, I, 18, 1869. _Falco candicans islandicus_, SCHLEG. Krit. übers, p. 1, 1844. _Falco lanarius_, FABER, Isis, 1827, 68. _Falco gyrfalco_, KEYSERLING & BLASIUS, Wirbelth. Eur. p. 135, 1840.