In this genus the bill is stout and slightly curved and is overhung by long hairs; the nostril is protected by a membrane; the wing is short and rounded, the first tour primaries being graduated; the tail is about equal in length to the wing, the feathers being slightly graduated.
* The genus contains but two species within our limits but these form numerous well-marked geographical races. The two species are very similar in colour but in habits differ considerably.
Key to Species and Subspecies.
A. Bill small; a conspicuous ring of white
feathers round the eye.
a. Chin and throat white, flanks tinged [p. 275.
olivaceous A. nepalensis nepalensis,
b. Chin and throat ochraceous like abdo-
men A. n. fratercula, p. 277.
B. Bill large; no ring of white feathers
c. Head not striped or only obsoletely so. (cephala, p. 277.
a1. Lower back and rump tinged rufous. A. poioicephala poioi-
b1. Lower back and rump grey like back.
a2. Under parts tinged rufous A. p. phayrei p. 278.
b2. No rufous on under parts.
a3. Grey of head well defined from
hack A. p. davisoni, p. 279.
b3. Grey of head blending into
colour of back A. p. brucei, p. 278.
d. Head and neck conspicuously striped.
c1. Stripes sooty-brown A.p. magnirostris, p. 280.
d1 Stripes deep black A. p. haringtoniae, p. 280.