Agriornis, [473], [475]

Air-cells, in Sula, [72]

Air-sac, [21];

in Tetraoninae, [201]

Aithurus, [426], [430];

A. polytmus, [433], [433]

Ajaja, young, [105];

A. rosea, [105]

Ala, [21]

Alaemon, [497], [498];