ERISMATURINjE pools K it in the otherwise dry beds of stream* It is extremely difficult to shoot them, on account of the readiness with which they dive : the instant the trigger is drawn, the hird is under water." B. lobata (Shaw), Bhaw'i Nat. Misc. pi. 255., PI. col. (.8. — Biziura doyk hollandic Steph. ; Anas carunctilata FieiU, Erismatura Pr. Bonap.* liill Qearly as long as the head, higher at the base than broad, the culmen suddenly curved to the front of the nostrils and then depressed, straight and the sides somewhat dilated near the tip, which is armed with a very narrow nail, enlarged and hooked beneath ; the nostrils oval and placed nearly in the middle of the bill. Wings short and concave, with the first two quills the longest. Tail long, wedge-shaped, and composed of narrow stiff feathers. Tarsi half the length of the middle toe, and compressed. Toes lengthened, the middle and outer ones of equal length, and the three anterior ones united by a full web ; the hind toe long, elevated, and margined by a lobed membrane ; the claws short, curved, and acute. The species are BCattered in various parts of both hemispheres. They are peculiarly aquatic birds, living on the large sheets of saline waters and rivers, especially those that run into the sea. In such places, they are generally seen in small societies of five or six individuals, and mostly apart from other species of water birds. Their bodies, except the head and neck, are entirely hidden beneath the surface of the water when swimming. The form of their bodies makes them extremely expert in diving, when seeking for molluscous animals and fish, on which they principally subsist. The nest is constructed of reeds and other aquatic plants, in such a manner that it floats on the surface of the water. 1. K. leueocephaJa (Scop.) Eyton, Gould's B. of Kur.pl. — Anas mena Pall. Reise ii. t. 11., Pall. Zoogr. t. 73., Hist, de 1'Egypt. Ois. pi. 10. f. 2. 2. E. rubida (Wils.) Bonap., Wils. Amer. Orn. pi. 71. f. 5, 6. — Type of Gymnura Xutt. (1834.) 3. E.ferruyhwa Eyton, Monogr. Anat. 170. 4. E. maccoa (A. Smith), Eyton, Monogr. Anat. 169. pi. 5. E. australis (Gould), Eyton, Proc. Z. S. 1836. 85. C. E. dominica (Linn.) Eyton, PI. enl. 9b'8. 0b"7. — Anas spinosa Gmeh ? 7. E. spinicaiifla (Vicill.) Ency. Meth. 356., Azara No. 42.9. — Anas oxyura Licht. Nesonetta. Bill shorter than the head, the width and elevation at the base equal, the culmen gradually sloping to the tip which is armed with a moderate-sized nail, the sides compressed and of equal breadth throughout ; the lamella; of the interior margins of the upper mandible small and widely set, strongest near the base; the nostrils near the base, lateral, and oval. Wings very short and pointed, with the second quill the longest. Tail short and wedge-shaped, with the end of the stem of each feather bare and rigid. Tarsi robust, about two thirds the length of the middle toe. Toes strong, with the outer toe shorter than the middle, and all the fore toes united by a full web ; the hind toe short, elevated, and somewhat lobed. The type of this genus is peculiar to the Auckland Islands, but its habits are at present unknown. N. aucklandica. — Mergus australis Homb. 8f Jacq. in Ann. Sc. Nat. ser. 2. xv. p. 320. ? This division was first established by the Prince of Canino under the denomination of Oxyura (Ann. Lyc. Xat. Hist, of A T eu- York, 1828, p. 3f)0.), which, having been previously used, was changed to the above in 1832. In 1832, Wagler proposed the name Crreonectes ; in 1834, Mr. Nuttall that of Gymnura ; and Mr. Gould, in 1836, that of Undina. September, 1844.