Fam. I. CASUARIIDAE.–Following Professor Salvadori,[21] Cassowaries may be divided into two groups: the first with the helmet laterally compressed, and the second where it is triangular and pyramidal, or even depressed. They are all large birds, though smaller than Emeus, which are only surpassed in size among existing forms by the Ostrich; the colour of the coarse but glossy hair-like plumage is black, and similar in both sexes; the hen is bigger than the cock, as is also the case in the Dromaeidae and Apterygidae. Of the first of the above groups, _Casuarius tricarunculatus_, from Warbusi in New Guinea, which is possibly a "sport," has two lateral wattles on the fore-neck and a third small median caruncle at a lower level. _C. bicarunculatus_, of the Aru Islands, has two long distant reddish-violet wattles, a black casque, bluish-green head, and blue neck with some red behind. _C. galeatus_ of Ceram, the species first known to ornithologists, is similarly coloured, though less brightly, and has the flesh-coloured throat-wattles close together, and a naked reddish-purple space on each side of the neck. The larger _C. australis_ of North-East Australia has a higher helmet, a brighter blue throat, and a few scattered hairs on the wattles, which Wall, who discovered the species, said were coloured with blue and scarlet. _C. beccarii_ of the Aru Islands, {34}Middle and South New Guinea, has the front and top of the casque black, its sides greenish, and its back yellowish; the head is grey-blue, the throat and sides of the neck are blue, the hind-neck is red and orange, a yellow streak running across to the mandible; a bare space on each side of the base of the neck is flesh-coloured, and the long single neck-wattle of the same colour is somewhat deeply divided at the tip.