Mr. Hutchins, in his notes on the Hudson’s Bay birds, states that the Pigeon Hawk “makes its nest on the rocks and in hollow trees, of sticks and grass, lined with feathers, laying from two to four white eggs, thinly marked with red spots.” As Hutchins has been found to be generally quite accurate in his statements, and as this description does not at all apply either to the nest or the eggs of the _columbarius_, it is quite possible that he may have mistaken this species for the Pigeon Hawk, and that this description of eggs and nests belongs not to _columbarius_, but to _richardsoni_. SUBGENUS RHYNCHOFALCO, RIDGWAY. Species. =F. femoralis.= Wing, 9.30–11.60; tail, 6.30–8.80; culmen, .60–.80; tarsus, 1.62–2.00; middle toe, 1.35–1.70. Second and third quills longest; first equal to or shorter than fourth. _Adult_ (sexes similar). Above uniform plumbeous, the secondaries broadly tipped with whitish. Tail darker terminally, crossed by about eight narrow, continuous bands of white, and tipped with the same. A broad postocular stripe, middle area of the auriculars, and entire throat and jugulum, white, unvariegated; the latter with a semicircular outline posteriorly, and the former changing to orange-rufous on the occiput, where the stripes of the two sides are confluent. Sides entirely uniform blackish (confluent on the middle of the abdomen), with narrow bars of white; posterior lower parts immaculate light ochraceous. _Young_ similar, but the jugulum with longitudinal stripes of blackish. _Hab._ Whole of Tropical America, exclusive of the West Indies, north to the southern border of the United States. [Illustration: =42076=, ♀. ½ =42076=, ♀. ¼ =42076=, ♀.] Falco (Rhynchofalco) femoralis, TEMMINCK. APLOMADO FALCON. _Falco femoralis_, TEMM. Pl. Col. 121, 343, 1824.—SPIX, Av. Braz. I, 18 (quot. Pl. Cl. 121), 1824.—VIG. Zoöl. Journ. I, 339.—STEPH. Zoöl. XIII, pt. 2, p. 39, 1826.—LESS. Man. Orn. I, 79, 1828; Tr. Orn. p. 89, 1831.—CUV. Reg. An. (ed. 2), I, 322, 1817.—SWAINS. Classif. B. II, 212, 1837.—NORDM. Erm. Reis. um die Erde, Atl. p. 16.—BRIDG. Proc. Zoöl. Soc. pt. 11, p. 109; Ann. Nat. Hist. XIII, 499.—D’ORB. Voy. Am. Merid. Av. p. 116, 1835.—TSCHUDI, Consp. Av. Wieg. Arch. 1844, p. 266; Faun. Per. p. 108, 1844.—CASS. Proc. Ac. Nat. Sc. Philad. 1855, p. 178.—STRICKL. Orn. Syn. I, 88, 1855. BREWER, Oölogy, 1857, 14, pl. iii, f. 22. _Hypotriorchis femoralis_, GRAY, Gen. B. fol. sp. 13, 1844; List B. Brit. Mus. p. 56, 1844.—HARTL. Syst. Ind. Azar. p. 3, 1847.—CASS. B. N. Am. p. 11, 1858.—COUES, Pr. Ac. Nat. Sc. Phil. 7, 1866.—GRAY, Hand List, I, 21, 1869. _Falco fuscocœrulescens_, VIEILL. Nouv. Dict. Hist. Nat. XI, 90, 1819. _Falco cyanescens_, VIEILL. Enc. Méth. III, 1234 (No. 40, Azara, juv. teste, Hartl.). _Falco thoracicus_, LICHT. Verz. Doubl. p. 62, 1823.