The sternum differs from that of _A. melleri_ by the lesser height of the keel and by the shape and direction of the anterior margin of the latter. The coracoid is longer and larger than in _N. bernieri_, but is much shorter than in _A. melleri_, though agreeing with that of the latter in shape, and by the plain almost ridgeless ventral surface of the shaft. The seven humeri vary in length from 70-78 mm., and agree in size with those of _N. punctata_, thus proving our species to be smaller than _A. melleri_. The two tarso-metatarsi are in poor condition; the right one measuring 42 mm. in length, thus indicating that _A. theodori_ was a bird with a shorter foot than _A. melleri_. Habitat: Mauritius. {105} CAMPTOLAIMUS LABRADORIA (GM.) (PLATE 36.) _Anas labradoria_ Gmelin, Syst. Nat. I, 2, p. 537 (1788--"Habitat gregaria in America, boreali." Ex Pennant and Latham.) _Anas labradora_ Latham, Ind. Orn. II, p. 859 (1790). _Rhynchaspis labradora_ Stephens, in Shaw's Gen. Zool. XII, 2, p. 121 (1824). _Fuligula labradora_ Bonaparte, Ann. Lyceum N.Y. II, p. 391 (1826). _Somateria labradora_ Boie, Isis 1828, p. 329. _Kamptorhynchus labradorus_ Eyton, Mon. Anat. p. 151 (1838). _Fuligula grisea_ Leib, Journ. Acad. Sc. Philad. VIII, p. 170 (1840--young bird). _Camptolaimus labradorus_ Gray, List. Gen. B. ed. 2, p. 95 (1841); Dutcher, Auk. 1891, p. 201, pl. II; 1894, pp. 4-12; Hartl. Abh. naturw. Ver. Bremen XVI, p. 23 (1895). _Camptolaemus labradorius_ Baird, B.N. Amer. p. 803 (1858); Baird, Brewer and Ridgway, Water--B. N. Amer. II, p. 63 (1884); Milne-Edw. and Oustalet, Centen. Mus. d'Hist. Nat., Notice Ois. éteint. p. 51, pl. IV (1893); Salvadori, Cat. B. Brit. Mus. XXVII, p. 416 (1895). The adult male and a young male, both in my museum, are represented on plate 36, but the young bird became too rufous, through the colour type reproduction, and should be somewhat more mouse-gray. Though first technically named by Gmelin in 1788, this duck was first described in 1785 by Pennant, in the Arctic Zoology II, p. 559, as follows:-- "Pied Duck. With the lower part of the bill black, the upper yellow, on the summit of the head is an oblong black spot; forehead, cheeks, rest of the head and neck, white; the lower part encircled with black; scapulars and coverts of wings white; back, breast, belly, and primaries, black; tail cuneiform, and dusky; legs black. The bill of the supposed female? resembles that of the male, head and neck mottled with cinereous brown and dirty white; primaries dusky; speculum white; back, breast, and belly clouded with different shades of ash-colour; tail dusky and cuneiform; legs black. Size of a common Wild Duck.