[44] As in the Polyborine forms of the Falconinæ.
[45] Extremes of sixty specimens.
[46] Sometimes there are more or less distinct linear streaks on the head and neck, or on the pectoral region.
[47] Sometimes the irregular markings above have a transverse tendency.
[48] Falco gyrfalco, var. gyrfalco (Linn.). Falco gyrfalco, Linn. S. N. 1766, p. 130.—Gmel. S. N. 275.—Schleg. Rev. Crit. II, Tr. de Fauc. pl. iii; F. van Nederl. Vog. pls. iii and iv.—Naum. Vog. pl. cccxci. Hierofalco gyrfalco, Schleg. Bonap. Rev. Zool. 1854, 535.—Newton, Oötheca Wolleyana, I, 87, pl. c. F. gyrfalco norvegicus, Wolley. Falco gyrfalco norwegicus, Schleg. Mus. Pays-Bas, 1862, 12. Falco candicans, var. γ, Blas.
Wing, 13.00–14.50; tail, 9.30; culmen, .98; tarsus, 2.50; middle toe, 1.92.
[49] Falco lanarius, var. lanarius (Schlegel). Falco lanarius, Schleg. Krit. Ueb. II, et 11.—Ib. Tr. Fauc. 6; Mus. Pays-Bas, Falcones 14; Abh. Zool. 16; Rev. 1844, 2; Naum. 1855, 252; Ibis, 1859, 86.—Bree, B. Eur. I, 1859, 37 (plate of adult!).—Tristram, Ibis, 284.—Gray, Hand List, I, 1869, 19, No. 171. Pelz. Ueb. der Geier und Falk. II, 1863, 20. Falco lanarius α, Schleg. Tr. Fauc. 23. Gennaia lanarius, Schleg.—Bonap. Rev. 1854, 535. Falco feldeggii, Schleg. Abh. Zool. 3–6.
[50] Falco lanarius, var. mexicanus (Licht.). Falco mexicanus, “Licht. Mus. Berol.”—Schleg. Abh. Zool. 1841, 15.—Schleg. Falcones, Mus. Pays-Bas, 1862, 18.—Pelz. Neb. der Geier und Falk. II, 1863, 19. “Falco sublanarius, Natterer.”—Pelz. Ueb. der Geier und Falk. II, 1863, 19.
[51] Falco lanarius, var. jugger (Gray). Falco jugger, Gray, Hardw. Ill. Ind. Zool. II, pl. xxvi, 1832.—Bonap. Consp. 24.—Gould, B. Asia, pl. i.—Jerdon, B. India, 30.—Strickl. Orn. Syn. 1855, 79, No. 129.—Schleg. Abh. pl. xv; Mus. Pays-Bas. I, 17. Falco lugger, Jerd. Aladr. Journ. X, p. 80; Ill. Ind. Orn. pl. xliv.—Blyth, Journ. Ass. Soc. Bengal, XI, 104. Falco thermophilus, Hodgs. Zool. Misc. 1844, 81. Falco lanarius? Blyth, J. As. Soc. Beng. XIX, 318.
[52] Extremes of more than one hundred specimens measured!