Fam. I. RALLIDAE.–The Rails constitute a somewhat generalized and very homogeneous Family, found in almost all parts of the world. The body is peculiarly compressed–enabling them to move with ease in dense vegetation–while the keel of the sternum is especially reduced in those flightless forms for which the group is remarkable. The strong bill varies in dimensions, being long in typical Rails, shorter and thicker in Crakes, decidedly curved in _Himantornis_, and reaching its maximum size among the Gallinules in _Porphyrio_ and _Notornis_, where it is subconical. A horny shield is present upon the forehead in _Megacrex_, _Habroptila_, the Gallinules and the Coots, which is usually rounded or truncated {244}posteriorly, but is reduced to a point in _Porphyriops_. This excrescence is in most cases red, but is sky-blue, light green, or dusky in _Porphyriola_, green in _Tribonyx_, blackish in _Megacrex_, white, yellow, or brown in _Fulica_. The lower part of the tibia is bare; the anteriorly scutellated metatarsus is seldom short, though occasionally very stout; the toes are long and slender with the elevated hallux weakest; the claws are fairly long, curved, and sharp. Somewhat shorter digits are found in _Tribonyx_ and _Pareudiastes_, _Fulica_ has broad lobes of skin along the front toes, while _Porphyriops_ and _Gallinula_ have narrow entire membranous margins to them. The wings are generally short and rounded, with ten or eleven primaries, and from eleven to sixteen secondaries, all the feathers being obtuse; but in many species these members are imperfectly developed, and their coverts actually hide the quills in such cases as _Ocydromus_ and _Notornis_. This retrograde tendency is clearly evidenced in the "Island Hen" of Tristan da Cunha (_Gallinula_ or _Porphyriornis nesiotis_) and the Mountain Cock of Gough Island (_G. comeri_), which flutter along without flying; in the Moho of Hawaii (_Pennula ecaudata_), _Ocydromus_ and _Notornis_ of New Zealand, and _Habroptila wallacii_ of Halmahera; not to mention _Eulabeornis_, _Porzanula_, _Nesolimnas_, _Cabalus_, _Pareudiastes_, and the extinct _Aphanapteryx_, _Aptornis_, _Diaphorapteryx_, and _Erythromachus_. In several flightless forms, as in the Dodo, the angle between the scapula and the coracoid is obtuse. The tail has from ten to fourteen rectrices, the usual number being twelve; these are short and usually soft, frequently with decomposed webs, and may be concealed by the coverts, as in _Megacrex_, _Amurolimnas_, and _Pennula_. Its form varies from narrow and pointed to comparatively broad and rounded. A large caruncle rises behind the frontal shield in _Gallicrex_ and _Fulica cornuta_, two knobs being found there in _F. cristata_: the wing, moreover, is often armed with a sharp spine. The nasal grooves are commonly long and deep; the pervious nostrils being in the hard sheath of the bill in Gallinules, and partially covered by a bony or horny