List of Specimens examined.—Nat. Mus., 2.
Measurements.—♂. Wing, 7.40–7.70; tail, 5.50; culmen, .50; tarsus, 1.40–1.42; middle toe, .95. Specimens, 2.
[67] Polyborus tharus. Falco tharus, Molina, Sp. Chil. p. 264, 343; 1782. Polyborus tharus, Strickl. Orn. Syn. I, 19, 1855. Falco cheriway, Jacq. Beyträg. p. 17, pl. iv, 1784. Polyborus cheriway, Rich. Schomb. Vers. Faun. Brit. Guiana, p. 741, 1840. Falco plancus, Gmel. Syst. Nat. p. 257, 1789. Falco brasiliensis, Gmel. Syst. Nat. p. 262, 1789 (et Auct.). Polyborus brasiliensis, Vig. Zoöl. Journ. I, 320, 1824. Caracara vulgaris, Less. Tr. Orn. p. 34; 1831. Polyborus vulgaris, Spix. Av. Bras. I, pl. i, a.
Adult male (21,850, South America; T. R. Peale). Forehead, crown, occiput, and wings brownish-black; middle wing-coverts fainter, with obscure whitish bars; primaries white in the middle (just beyond the coverts), this portion having obsolete washes of grayish, in form of faintly indicated transverse bars; basal three-fourths of the tail white, with numerous narrow, washed bars of grayish, these becoming more faint toward the base; tail with a terminal zone of black, about two inches broad. Cheeks, chin, and throat soiled white, unvaried; body in general (including neck, breast, sides, abdomen, back, and scapulars) transversely barred with black and white, the white prevailing anteriorly; beneath, the black bars grow gradually wider posteriorly, giving the tibiæ and femorals a uniformly blackish appearance; on the back and scapulars also the black bars exceed the white in width, but they are very sharply defined, regular, and continuous; rump, upper and lower tail-coverts, white, with numerous faint bars of grayish. Under side of the wing black; outer six primaries white in the middle portion, beyond the coverts, this patch extending obliquely across; secondaries rather broadly barred on basal two-thirds with black and white, leaving the terminal third unvaried. Third quill longest; fourth scarcely shorter; second intermediate between fifth and sixth; first a little longer than seventh. Wing, 16.00; tail, 6.50; tarsus, 3.50; middle toe, 1.75.
Young (13,923, South America; T. R. Peale). Forehead, crown, occiput, nape, back, wings, and lower parts dark sepia-brown; feathers of the breast, sides, and abdomen marked centrally with a broad longitudinal stripe of soiled fulvous-white; those of nape and back more obsoletely striped, and variegated irregularly at ends with the same; wing-coverts passing terminally into pale brownish; secondaries obscurely barred with the same. Cheeks, chin, and throat unvariegated soiled white; tibial feathers with shaft-stripes of pale fulvous. Rump, tail-coverts, and tail as in adult. Several specimens from Buenos Ayres (Conchitas; Wm. H. Hudson), and one from Paraguay (59,236; T. J. Page, U. S. N.), have the black of the lower part of the abdomen and flanks quite continuous. There is never, however, in South American specimens, an approach to the peculiar characters of auduboni, as defined.
List of Specimens examined.—Nat. Mus., 7; Bost. Soc., 4; Philad. Acad., 3; N. Y. Mus., 3. Total, 17.
Measurements.—♂. Wing, 16.00–17.20; tail, 10.00–11.00; culmen, 1.20–1.30; tarsus, 3.70–3.90; middle toe, 1.75–2.15. Specimens, 2. ♀. Wing, 17.70; tail, 10.00; culmen, 1.41; tarsus, 4.20; middle toe, 2.30. Specimens, 1. Sex? Wing, 15.50; tail, 10.00; culmen, 1.30; tarsus, 3.65; middle toe, 1.90. Smallest of 4.
[68] Pandion haliætus, var. haliætus (Linn.). Aquila haliætus, Briss. Orn. I, 440, pl. xxxiv. Falco haliætus, Linn. S. N. I, 1766, 129. Pandion haliætus, Less. Man. Orn. I, 86. Falco arundinaceus, Gmel. 1733. Pandion fluvialis, Savign. Descr. Egyp. I, 96, 1809. Pandion alticeps and planiceps, Brehm, Vög. Deutschl. 33, 1831. Pandion indicus, Hodgs. Cat. Gray’s Misc. 81.
Specimens examined.—Nat. Mus., 3; Bost. Soc., 2; Philad. Acad., 3; other sources, 10. Total, 18.
Measurements.—♂. Wing, 18.00–18.50; tail, 8.50–8.70; culmen, 1.20–1.30; tarsus, 1.95–2.00; middle toe, 1.50–1.80. Specimens, 4. ♀. Wing, 19.50–20.50; tail, 9.00–9.50; culmen, 1.35–1.45; tarsus, 2.00–2.10; middle toe, 1.85–1.90. Specimens, 4.