Fam. V. CRACIDAE.–These birds are almost identical in structure with the _Megapodiidae_, though sharply contrasted in their arboreal habits and their style of breeding. They may be divided into the Sub-families (1) _Cracinae_ or Curassows, (2) _Penelopinae_ or Guans, and (3) _Oreophasinae_. Of the first of these, where the maxilla is higher than it is broad, the genus _Crax_ has a soft {195}cere, and nostrils in the middle of the bill, with the addition in many cases of frontal excrescences and wattles; _Nothocrax_, _Pauxis_ and _Mitua_ have the beak horny and the nostrils basal, _Pauxis_, moreover, being distinguished by a large knob on the forehead, and _Mitua_ by its short, highly-compressed bill with swollen culmen. The remaining Sub-families have the maxilla depressed and broader than it is high; _Penelope_, _Penelopina_ and _Pipile_ exhibit bare throats with a median wattle, _Ortalis_ a mere band of bristly-shafted feathers down the middle, and _Aburria_ a feathered throat and vermiform wattle, while _Chamaepetes_ shews neither wattle nor bare skin, and _Oreophasis_, the sole tenant of the _Oreophasinae_, a naked crown, surmounted by a cylindrical helmet. The males of _Crax_, _Pauxis_, and _Mitua_, and both sexes of _Penelope jacucaca_, have the trachea looped, and sometimes extended to the posterior end of the keel of the sternum; other forms lack the convolutions, but in several the state is unknown. The range covers Central and South America, excluding the Greater Antilles, Chili and Patagonia, but one species (_Ortalis vetula_) even reaches as far north as Texas.