In certain respects this order, consisting of the Bails, Finfeet, Cranes, Bustards, and some other families of schizognathous birds, resembles the desmognathous Anisodactyli. Modern ornithologists differ greatly as to the affinities of these groups to each other and to birds belonging to other orders. By some writers the Rallidae and the Heliornithidae are placed in an ordinal group by themselves *, by others the Bails and Cranes with some other families are associated together and the Bustards transferred to the neighbourhood of the Plovers t. As in the case of the Anisodactyli, so in the present instance I adopt Gadow's classification partly in order to avoid increasing the number of ordinal groups, for if the Bails are made an order distinct from the Cranes; the Bustards, and probably the Finfeet, would have equal claims to ordinal distinction. In using for the present order the Linnean term Grallae, the example set by Newton is followed, but he omitted the Bustards.
In the Grallae the hind toe when present is slightly raised, the legs are generally long, and part of the tibia is bare. All are schizognathous and none possess basipterygoid processes. The vomer is always present and the angle of the mandible is truncated. There are two carotids. Nostrils pervious (except in Rhinochetus). Ambiens muscle always present, and caeca generally well developed. The deep flexor tendons are, as a rule, Galline (peculiar in Heliornithidae and modified in Otididae). The young of most of the families are hatched covered with down and able to run almost immediately, but in Heliornis the young are hatched helpless and nearly naked. All, so far as is known, lay double-spotted eggs—that is, eggs with one set of spots distinct and deeply coloured and a second set. often purplish or grey, less distinct, and apparently beneath the surface. To the Grallae belong several families ; but there are great differences of opinion as to their affinities, and it is sufficient to deal herewith the four represented in India. They may be referred to three suborders :—
a. Oil-gland tufted ; a hallux present.
a1. Holorhinal; sternum with a single notch on each side…………………….FULICARIAE.
b1. Schizorhinal; sternum without notches…………………….GRUES.
b. No oil-gland ; holorhinal; sternum with two notches on each side ; no hallux…………………….OTIDES.
* For instance, Sclater, ' Ibis,' 1880, p. 408 ; Sharpe, Oat. B. M. vol. xxiii; Furbringer,' Untersuchungen,' p. 1566. Newton, "Ornithology," Encycl. Brit. p. 46. P. Z. S. 1892, p. 244 ; id. in Bronn, Kl. u. Ord. Thier-reichs, vi. 4, p. 178.