The magnificent Firebacks (_Lophura_) have, so far as is known, similar habits to the members of _Gennaeus_, though they are stronger on the wing, and utter mellower notes in their forest retreats; {215}the tail is vaulted, the cheeks exhibit patches of rugose blue skin–red in _L. diardi_–while the male has a pair of spurs and an erect crest with bare-shafted plumes. _L. nobilis_ of Borneo is purplish-blue with fiery chestnut rump-region, golden lower breast, black head, throat, and wings, the four median rectrices being entirely buff and the lateral black with buff markings; _L. vieilloti_ of Siam, the Malay Peninsula, and Sumatra has the lower breast black, and the two middle rectrices white, _L. ignita_ of China differing in its chestnut-spotted flanks; _L. diardi_ (_praelata_) of Siam, Cambodia, and Cochin China has a grey and black mantle, neck, and breast, a golden buff lower back, and crimson-tipped rump-feathers. The females have the mantle red-brown or chestnut, and outer rectrices of the latter colour in _L. vieilloti_, but black in _L. nobilis_; in _L. diardi_ the black wing-coverts have wide buff bars. This sex of _L. ignita_ seems to be unknown. _Acomus_ has naked cheeks, but no crest or wattles; the tail is vaulted, and a pair of spurs is found in both sexes. _A. erythrophthalmus_ of the southern Malay Peninsula and Sumatra is chiefly purplish- or bluish-black with fiery golden lower back, rich buff tail, and white wing-markings; _A. pyronotus_ of Borneo exhibits white shaft-stripes on the breast; _A. inornatus_ of West Sumatra, of which the male only has been discovered, has black plumage margined with dark blue-green, therein somewhat resembling the hens of its congeners, which are black glossed with purplish-blue. In habits this genus apparently resembles _Lophura_.