"Young female.--General color above brown, with whitish brown margins to the feathers; lesser wing-coverts brown, the inner ones rufous, with brown centers; median and greater coverts pale rufous, white externally toward the ends and round the tips; alula dark brown, externally rufous; primary-coverts uniform dark brown; quills dark brown fringed with white round the ends, and crossed with blackish brown bars, four in number, one subterminal; secondaries paler brown, externally rufous; upper tail-coverts tawny-rufous, edged with white and with dark brown centers; tail-feathers dark brown, narrowly fringed with white at the ends, and crossed with blackish bands, the subterminal one very broad, but not nearly so wide as the preceding interspace; a crest of white feathers, the long ones freckled with brown; head, nape, and hind neck, lores, sides of face, ear-coverts, cheeks, sides of neck, and entire under surface of body pure white, slightly washed with rufous on the head and hind neck; the breast, abdomen, and under tail-coverts washed with creamy buff; the sides of the body and flanks with slight indications of spots of pale tawny buff; under wing-coverts and axillars like the breast; quills below ashy gray, with blackish bars on the primaries. Length, 394; culmen, 29; wing, 274; tail, 178; tarsus, 35. "The typical [=type] specimen, though manifestly immature, differs thoroughly from the young of B. sumatrensis, and I feel sure that the adult bird, when discovered, will be markedly distinct." (Sharpe.) "Rare and shy. Iris, legs, and feet yellow; nails black; bill black, slaty at base; bare flesh of head greenish yellow. One specimen had been eating crabs when shot. "A male measures 457 in length; wing, 312; tail, 199; culmen, 27; tarsus, 76; middle toe with claw, 40. A female, 457 in length; wing, 305; tail, 208; culmen, 26; tarsus, 64; middle toe with claw, 43." (Bourns and Worcester MS.) The adult of this rare species appears to be undescribed. Genus MICROHIERAX Sharpe, 1874. Bill strong; edge of mandible with a double notch forming a sharp tooth; cere small; no crest; first primary nearly equal to second and third which are the longest; secondaries short; tarsus and feet strong; plumage black and white; length less than 200 mm. Species. a1. Slightly smaller. ... erythrogenys (p. 238) a2. Slightly larger. ... meridionalis (p. 239) 196. MICROHIERAX ERYTHROGENYS (Vigors). PHILIPPINE FALCONET. Hierax erythrogenys Vigors, Proc. Zool. Soc. (1831), 96. Microhierax erythrogenys Sharpe, Cat. Birds Brit. Mus. (1874), 1, 369; Hand-List (1899), 1, 273; McGregor and Worcester, Hand-List (1906), 44; McGregor, Philippine Jour. Sci. (1907), 2, sec. A, 323. Bohol (McGregor); Luzon (Meyer, Möllendorff, Everett, Steere Exp., Whitehead, McGregor); Mindoro (Bourns & Worcester, Porter); Negros (Keay).