550. Spatula Rhynchotis Vol. VII. Pl. 12. This bird is, I believe, restricted to Australia. Genus MALACORHYNCHUS, _Swains._ A very delicate form, of which the single species, confined to Australia, is the only one known. 551. Malacorhynchus membranaceus Vol. VII. Pl. 13. Genus DENDROCYGNA, _Swains._ This form is found in India, Africa, America and Australia: the bird I have separated into a distinct genus, under the appellation of _Leptotarsis_, should be included in this genus, the difference which it presents being too slight to warrant their separation. 552. Dendrocygna arcuata Vol. VII. Pl. 14. 553. Dendrocygna Eytoni. Leptotarsis Eytoni, _Gould_ Vol. VII. Pl. 15. “Many of the reaches,” says Captain Stokes, when speaking of the river Adelaide of the north-western part of Australia, “swarmed with wild fowl, consisting almost wholly of ducks, which, from a habit of perching on the trees, have received the name of Wood Ducks. Their singularly long legs, with the web very much arched near the toes, gives great pliability to the foot and a power of grasping, which enables them to perch on trees. When on the wing they make a peculiar pleasing, whistling sound, that can be heard at a great distance, and which changes as they alight into a sort of chatter. Their perching on trees is performed in a very clumsy manner, swinging and pitching to and fro. We subsequently often found them on the rivers of the north coast, but not within some miles of their mouths or near their upper waters, from which it would appear that they inhabit certain reaches of the rivers only; we never found them in swamps. The farthest south they were met with was on the Albert River, in the Gulf of Carpentaria, in lat. 18° S., which gives them a range of six and a half degrees of latitude over the northern part of the continent. These ducks are the _Leptotarsis Eytoni_ of Mr. Gould.” Genus NYROCA, _Flem._ Two species at least of this genus are known, one inhabiting Europe and India and the other Australia: both have the irides white. 554. Nyroca Australis, _Gould_ Vol. VII. Pl. 16. Genus ERISMATURA, _Bonap._ The members of this genus, although but few in number, are found in Europe, Asia, Africa, America and Australia. 555. Erismatura Australis Vol. VII. Pl. 17. This species, the only one of the genus inhabiting Australia, is, I believe, strictly confined to the western parts of the country, as hitherto it has not been seen elsewhere. Genus BIZIURA, _Leach_. A genus of which only a single species is known to exist, and which is singularly different from every other member of the family. It is strictly Australian, and may be regarded as one of the anomalies of its fauna.