(Rallidae; Ϯ Invisible Rail H. wallacii) Gr. ἁβρος habros soft, delicate; πτιλον ptilon feather; "HABROPTILA. Bill longer than the head, strong, with the culmen at the base elevated, broad, rounded posteriorly, and gradually descending towards the tip, which is suddenly curved; the sides compressed to the tip, which is slightly emarginated; the gonys moderate, slightly angulated and advancing upwards; nostrils placed in a membranous groove, which extends beyond the middle of the bill, with the opening linear and near the base of the groove. Wings very short, lax, with the fourth to seventh quills equal and longest. Tail very short and lax. Tarsi robust, as long as the middle toe, and covered with transverse scales. Toes rather robust and long; the lateral toes equal, the hind toe moderate and strong. Claws moderate and compressed. Plumage in general very lax. The wings armed at the bend of the shoulder with a small spine. HABROPTILA WALLACII. ... This curious bird approaches the Ocydromi in the shortness and softness of its wings; the feet are those of a Porphyrio. Yet its general appearance might cause it to be taken, at first sight, for a species of Hæmatopus." (G. Gray 1860); "Habroptila G. R. Gray, Proc. Zool. Soc. London, 1860, p. 365, pl. 172. Type, by monotypy, Habroptila wallacii G. R. Gray." (Peters 1934, II, 178).