Aethiopsar, [561]

Aethopyga, [569]

Aethorhynchus, [504]-[506]

Aex, [111], [112];

A. galericulata, [114], [133];

A. sponsa, [133]

Aftershaft, of feathers, origin of, [3];

absent, in Alcedinidae, [383];

in Apteryx, [39];

in Hornbill, [390];