The intrinsic muscles of the syrinx fixed to the ends of the bronchial semi-rings. The edges of both mandibles smooth, or the upper one simply notched; hinder aspect of tarsus smooth, composed of two entire longitudinal laminae; wing with ten primaries; tongue non-tubular; nostrils clear of the line of forehead, the lower edge of the nostril generally nearer to the commissure than the upper edge is to the culmen; plumage of the nestling like that of the adult but paler ; nostrils hidden by feathers and bristles; rectrices twelve ; sexes absolutely alike; an autumn moult only.
In this family the first primary is long, exceeding half the length of the second, whilst the bill exceeds its depth in length. It contains the Crows, Magpies, Jays, Nutcrackers, and Choughs. All species are resident within the limits of this work except the Rook and the Hooded Crow, which are winter visitors to the North and .North-West. Their summer quarters are, however, not far off and their migrations are only partial and local The members of the genera Corvus, or the true Crows, Pica, the Magpies, Nucifraga, the Nutcrackers, and Pyrrhocorax, the Choughs, are birds of wide distribution but the members of the other genera are nearly all restricted to small areas.
The Corvidae vary a good deal inter se in structure and habit. In one or two genera the nostrils are not so completely hidden by bristles as in the typical Crow. The majority feed completely on the ground, others are strictly arboreal. They all agree in laying four or five spotted eggs except certain species of the genus Podoces, which lay white eggs in burrows. The mode of nidification of the remaining genera varies greatly, some species breeding in holes of trees and cliffs, the others, the majority, constructing large nests of sticks and twigs. Most of them are omnivorous, but some of the smaller tropical species appear to confine their diet to insects.
The Corvidae, as a family, have few characters in common, and yet there is no group of: birds which is more easily recognized.
Key to Genera.
A. Nostrils distant from forehead about one-
third length of bill; narial bristles rigid and straight, reaching to about middle of bill; or rictal bristles and feathers of face absent.
a. Tail much shorter than wing CORVUS, P. 20.
b. Tail much longer than wing PICA, p. 37.
B. Nostrils distant from forehead less than one-
quarter length of bill; narial bristles or plumes short, never reaching to middle of bill.
c. Tail greatly graduated, outer feathers less
than half length of tail.
a1. Middle tail-feathers uniformly wide throughout or widening gradually to¬wards tip.
a2. Bill red or yellow.
a3. Tail more than twice length of
wing UROCISSA, p. 40.
b3 Tail less than twice length of
wins: CISSA, p. 45.
b2 Bill black DENDROCITTA, p. 47.
b1. Middle tail-feathers suddenly broadening
towards tip CRYPSIRHINA, p. 56.
d. Tail not much graduated, outer feathers
more than half length of tail,
c1. Graduation of closed tail less than length of tarsus; rictal bristles extremely long ………………………………………………………PLATYSMURUS. p. 58.
d1. Graduation of tail more than length of tarsus; rictal bristles moderate or obsolete.
c2. Nostrils nearer edge of culmen than to lower edge of upper mandible,
c3. Bill about half length head,
deep and notched GARRULUS, p. 59.
d3 Bill about same length as head,
slender and not notched NUCIFRAGA, p. 66.
d2. Nostrils nearer lower edge of upper mandible than to culmen.
e3. Wings long, falling short of the tip of the tail by less than length of tarsus …………………………………………………..PYRRHOCORAX, p.69.
f3. Wings short, falling short of the tip of the tail by more than length of tarsus PODOCES, p. 71.