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Show 1876.] NEOTROPICAL ANATID.E. 403 Mr. Darwin, in describing its habits, says that its wings are too small and weak to allow of flight, but that by their aid, partly swimming and partly flapping the surface of the water, it is enabled to move very quickly. He adds that he is nearly sure that it moves its wings alternately instead of, as in the case of other birds, both together. It is able to dive only a short distance. It feeds on mollusks, obtained from floating kelp and tidal rocks. Dr. Cunningham remarks that the Loggerhead Duck is very plentiful in the eastern part of the Straits of Magellan, and that it also occurs in abundance at the Falkland Islands. He adds that the bird is exceedingly hard to kill. In the latter islands Capt. Abbott found them in great numbers, where they breed along the coast. The nests are readily found by searching the shore just opposite where the male bird is seen swimming by himself. The old female flutters off to the water, being quite unable to fly. It lays from the end of September to the end of November, making its nest in the long grass or a bush of some kind. The usual complement of eggs is seven, as many as nine being sometimes found. The " Flying Loggerhead" is probably the young bird of this species, though it would appear from Capt. Abbott's remarks that it breeds when still able to fly; for one flew out of a nest that he found, high up into the air. Capt. Abbott considers the flying bird distinct; but Dr. Cunningham's view seems to be the correct one, viz. that "the so-called M. patachonicus is only the young of M. cinereus, the peculiarity being that the power of flight departs from the bird as it grows old" *. The anatomy of this Duck is fully described in Dr. Cunningham's memoir in the Society's ' Transactions.' Subfamily V. ERISMATURINAE. Genus E R I S M A T U R A . Type. Oxyura, Bp. Syn. N . A. Birds, p. 390 (1828) E. rubida. Gymnura, Nuttall, Man. Ornith. ii. p. 426 (1834) .. E. rubida. Undina, Gould, B. of Eur. vol. v. pl. 383 (1836) .. E. mersa. Erismatura, Bp. Comp. List, p. 59 (1838) E. mersa. Cerconectes, Wagler, Ibis, 1832, p. 282 E. mersa. Bythonessa, Gloger, Handb. d. Nat. p. 472 (1842). . E. mersa. Of the three species of this quasi-cosmopolitan group one is only found in the northern part of the Neotropical region, a second is very widely spread in tropical America, and the third may be regarded as an Antarctic form. 1. ERISMATURA RUBIDA. * Anas rubida, Wils. A m . Orn. vii. p. 128, t. 81 (1814). Erismatura rubida, Bp. Comp. List, p. 59 ; Baird, Bird of N. A. p. 811 ; Eyton. Mon. Anat. p. 171 ; Gundl. Repert. F.-N. i. p. 390, et J. fur Orn. 1875, p. 384 (Cuba); Cab. J. fiir Orn. 1857, p. 230 * See P. Z. S. 1871, p. 262, and Trans. Zool. Soc. vii. 493. |