males strut and gesticulate like Turkeys when courting, while incubation lasts about three weeks. The colour is black, the naked head being dusky and the upper neck somewhat corrugated; the bill is blackish with light tip, the irides are brown. Fossils referred to this Family are met with in North and South America.[124] The points wherein the Cathartae differ from the Accipitres {141}having been already noticed (p. 137), it only remains to discuss in detail the several families comprised in the latter Sub-Order. [Illustration: FIG. 38.–Secretary-Bird. _Serpentarius secretarius._ × ⅑.] Fam. II. SERPENTARIIDAE.–This contains only _Serpentarius secretarius_, the African Secretary-Bird–now generally recognised as an Accipitrine form–which is most common in the south, though extending northwards to the Gambia, Khartum, and Abyssinia. It was first accurately made known in 1769, from an example living in the menagerie of the Prince of Orange, by Vosmaer, who was told that at the Cape of Good Hope it was called "Sagittarius," or Archer, from its habit of striding like a bowman about to shoot, and that this name had been corrupted into "Secretarius." Subsequently–about 1770–a pair was {142}brought alive to England.[125] The appellation is evidently, however, derived from the nuchal tuft, which bears a fancied resemblance to the pen of a clerk stuck above his ear. Standing some four feet high on very long legs, this bird gives the impression of a Heron or Crane, and is a striking object on its native plains. The short strong beak is greatly arched, and is not toothed, the neck is elongated, the body comparatively small, and the metatarsus boldly scutellated all round, the short straight toes with their blunt claws being joined anteriorly by small membranes. The ample wings have eleven pointed primaries and seventeen secondaries; the graduated tail of twelve rectrices has the two obtuse median feathers drooping and much prolonged. Down is evenly distributed over the adults, and an aftershaft is present. The general colour is bluish-grey, with black wing-quills, lower back and vent; the loose pendent crest on the occiput and nape contains ten plumes in pairs, the longer being black and the shorter grey with black ends; the tail is grey, subterminally barred with black and tipped with white, which sometimes shews on the short close flank-feathers. The long cere, naked sides of the face, and feet are yellow, the irides hazel. The sexes are similar.