_? Accipiter falco maculatus_, Briss. Orn. I, 329. _? Falco nævius_, GMEL. S. N. 1789, 271. _Falco communis_ ζ, and _F. communis_ η, LATH. Ind. Orn. p. 31. _Falco communis_, COUES, Key, 1872, 213, f. 141. _Falco peregrinus_, ORD. Wils. Am. Orn. 1808, pl. lxvi.—SAB. L. Trans. XII, 529.—RICH. Parry’s 2d Voy. App. 342.—IB. F. B. A. II, 1831, 23.—BONAP. N. Y. Lyc. II, 27.—IB. Isis, 1832, 1136; Consp. 1850, 23, No. 4.—KING, Voy. Beag. I, 1839, 532.—JAMES. Wils. Am. Orn. 677, Synop. 1852, 683.—WEDDERB. Jard. Contr. to Orn. 1849, 81.—WOODH. Sitgr. Zuñi, 1853, 60.—GIRAUD, B. Long Island, 1844, 14.—PEALE, U. S. Ex. Ex. 1848, 66.—GRAY, List B. Brit. Mus. 1841, 51. _Falco anatum_, BONAP. Eur. & N. Am. B. 1838, 4.—IB. Rev. Zoöl. 1850, 484.—BRIDG. Proc. Zoöl. Soc. pl. xi, 109.—IB. Ann. N. H. XIII, 499.—GOSSE, B. Jam. 1847, 16.—CASS. B. Cal. & Tex. 1854, 86.—IB. Birds N. Am. 1858, 7.—DE KAY, Zoöl. N. Y. II, 13, pl. iii, f. 8.—NUTT. Man. 1833, 53.—PEAB. B. Mass. 1841, 83.—STRICKL. Orn. Syn. I, 1855, 83.—BLAKIST. Ibis, III, 1861, 315.—MARCH, Pr. Ac. N. S. 1863, 304. _Falco nigriceps_, CASS. B. Cal. & Tex. I, 1853, 87.—IB. Birds N. Am. 1858, 8.—STRICKL. Orn. Syn. I, 85.—COOP. & SUCKL. P. R. R. Rep’t, VII, ii, 1860, 142.—GRAY, Hand List, I, 1869, 19, No. 166.—SHARPE, Ann. & Mag. N. H. _Falco orientalis_, (GM.) GRAY, Hand List, I, 1869, 19, No. 165 (in part). _? Falco cassini_, SHARPE, Ann. & Mag. N. H. SP. CHAR. _Adult_ (♂, 43,134, Fort Resolution, Brit. N. Am., June; J. Lockhart). Upper parts dark bluish-plumbeous, approaching black anteriorly, but on rump and upper tail-coverts becoming fine bluish plumbeous-ash. On the head and neck the continuous plumbeous-black covers all the former except the chin and throat, and the back portion of the latter; an invasion or indentation of the white of lower parts up behind the ear-coverts separating that of the cheeks from the posterior black, throwing the former into a prominent angular patch; forehead and lores grayish. All the feathers above (posterior to the nape) with transverse bars of plumbeous-black, these most sharply defined posteriorly, where the plumbeous is lightest. Tail black, more plumbeous basally, very faintly paler at the tip, and showing ten or eleven transverse narrow bands of plumbeous, these most distinct anteriorly; the bars are clearest on inner webs. Alula, primary and secondary coverts, secondaries and primaries, uniform plumbeous-black, narrowly whitish on terminal margin, most observable on secondaries and inner primaries. Lower parts white, tinged with delicate cream-color, this deepest on the abdomen; sides and tibiæ tinged with bluish. Chin, throat, and jugulum immaculate; the breast, however, with faint longitudinal shaft-streaks of black; sides, flanks, and tibiæ distinctly barred transversely with black, about four bars being on each feather; on the lower tail-coverts they are narrower and more distant; on