Caeca wanting; oil-gland tufted; sternum with two deep posterior notches, one on each side ; manubrium not forked, flat and broad, a perforation behind it; spinal feather-tract well-defined on the neck, and forked on the upper back. Only the left carotid is present. Deep plantar tendons free from each other, as far as the subdivision of the flexor perforans digitorum, but a vinculum from the flexor longus hallucis leads to that slip from the other tendon which supplies the third digit or middle toe, the union of the vinculum with the slip taking place below, not above the root of the toe *.
The Hoopoes have been shown by numerous observers, especially Murie (Ibis, 1873, pp. 181-211), to be closely allied both in struc¬ture and nesting-habits to the Hornbills. There are two families, Upupidae and Irrisoridae, the latter confined to Africa.