That most abnormal form _Rostrhamus sociabilis_, the Awl-billed or Everglade Kite, ranging from Florida and Cuba to Bolivia and Argentina, is slaty-black, with white base and tip to the brownish emarginate tail, orange cere and feet, and crimson irides. The extraordinarily slender bill with long terminal hook no doubt assists greatly in extracting from their shells the molluscs, such as _Ampullaria_, on which this species entirely subsists, while its long legs and sharp talons help to secure the prey in the muddy swamps it frequents. Mr. Gibson[140] tells us that it is to some extent gregarious, and is often seen slowly beating over the {172}marshes, or poised aloft with its broad expanded tail alone in motion, a "creaking" or "neighing" alarm-note being apparently the only cry. Twenty or thirty nests are commonly built close together, and are slight platforms of twigs or plant-stems, with a lining of aquatic herbage, supported on the reeds or bushes a few feet above the water. The two or three eggs are whitish with reddish- or yellowish-brown and grey blotches. The breeding-quarters are constantly changed. _Machaerorhamphus alcinus_, of Tenasserim, Malacca, Borneo, Sumatra, and New Guinea, is especially remarkable for the wide gape of the short bill, which recalls that of the Caprimulgidae. All the tail-coverts are unusually elongated, a fine crest of pointed feathers adorns the occiput, and the plumage is black with a chocolate tinge, the throat and middle of the chest being white, with a broad black streak down the former. _M. anderssoni_, of Damara-Land, the Cameroons, and Madagascar, known to have crepuscular tendencies and to feed partly on bats, is smaller, and has a white abdomen; _M. revoili_, of Somali-Land, is intermediate.