The intrinsic muscles of the syrinx fixed to the end of the bronchial semi-rings; both mandibles finely and evenly serrated on the terminal third of their edges; bill short and triangular; primaries nine or ten ; the nestling resembling the adult female; one moult in the year ; rectrices twelve ; rictal bristles short.
The Dicaeidae form a very compact and natural family of birds, which may be known at once, and separated from all other Passeres except the Nectariniidae, by the peculiar serrations on the edges of both mandibles, as shown in the accompanying cut.
This character holds good in all the species of this family without exception. A lens is generally necessary to observe the serrations, but frequently they may be seen with the naked eye, especially if the open bill is held against a sheet of white paper.
The Dicaeidae are all small birds, generally of brilliant plumage. In most species the sexes differ in colour, in some they are alike. The young resemble the adult female. They are all resident, not even migrating locally.
This family forms a connecting-link between the nine-primaried and the ten-printaried Passeres, some of the genera possessing nine of these feathers, and others ten. They all have twelve tail-feathers. The nostrils are covered by a large oval process leaving a lunar aperture; the rictal bristles are short, but the naral bristles are sometimes greatly developed. The tail is always short, and the tarsus is never lengthened.
The Flower-peckers are remarkable for the beauty of their nests, which are frequently pear-shaped, and suspended from a branch. The eggs are invariably white except in Piprisoma, in which they are spotted.
Key to the Genera,
a. With nine primaries, the first reaching to the tip of the wing.
a1. Bill slender; the lower line of the inferior mandible almost straight…………………DICAEUM, p. 375.
b1. Bill thick; lower mandible swollen ; its lower edge much angulate.
a2. Tail rounded; nostrils covered by long hairs…………………ACMONORHYNCHUS, p. 381.
b2. Tail square; nostrils perfectly bare of hairs…………………PIPRISOMA, p. 382.
b. Wing with ten primaries, the first one small.
c1. First primary about equal to the tarsus…………………PRIONOCHILUS, p. 384.
d1. First primary not longer than the hind toe…………………PACHYGLOSSA, p. 385.