BIRDS — EKISMATURINAE — ERISMATtTRA RUBIDA. 



811 



Sub-Family ERISMATUEINAE. 



The most prominent character of the Erismaturinae is found in the very rigid tail feathers 

 with the much abbreviated coverts, which leave the greater portion of the tail exposed. There 

 are peculiarities in the nail at the end of the bill in Erismatura not found in the other sub-families. 



ERISMATURA, Bonap. 



Oiywra, BoNAP. Syn. 1828. Tyfi, Anas nihida. Sufficiently distinct from OxywnM. ? lype Anmleucocephala, &co}^. 

 Erismatura, Bokap. Saggio, etc., 1832. 



Ch. — Bill broad, rather high at the base, much depressed, and bent upwards. Upper lateral angle of bill running back on 

 the forehead some distance; farther than the lower edge of the bill. Nostrils reaching to the middle of the bill, rather small. 

 Portion of nail seen from above very narrow and linear ; bent abruptly downwards and backwards at the tip so as to be 

 invisible from the upper surface. Tarsi very short, scarcely more than one-third the long feet. Tail very stiff; of 18 feathers. 

 The coverts above and below very much abbreviated, so as to expose the greater part of the tail. The feathers narrow 

 linear. The shafts very large, and channelled on the under surface near the base. Wings very short, and incurved at the end. 



Of this genus there are several species belonging to America, although but one is well 



established as an inhabitant of the United States. Dr. Cabot, however, has recently announced 



the occurrence of the E. dominica on Lake Champlain. 



Comparative measurements of species. 



ERISMATURA RUBIDA, Bonap. 



Ruddy Duck. 



.anas rubida, Wilson, Am. Orn. VIII, 1814, 128, 130 ; pi. lx.xxi. 



.anas {Fuligula) rubida, Bon. Obs. Wils. 1825, 268. 



FuUgula (Oxyura) rubida, Bon. Syn. 1828, 390. 



Fuligula (Gymnura) rubida, Nuttall, Man. II, 1834, 426. 



FuUgula rubida, Sw. F. Bor. Am. II, 1831, 455.— AuD. Orn. Biog. IV, 1838, 326 ; pi. 343.— Is. Syn. 288.— Ib. 



Birds Am. VI, 1843, 324 ; pi. 399. 

 Erismatura rubida, Bonap. List, 1838. — Etton, Mon. Anat. 1838, 171. 

 .9nas jamaicensis , "Lath." — Ord, ed. Wilson, Vill, 1825, 138. 

 Sp. Ch. — Bill grayish blue. Top of head and nape black. Sides of head below the eyes, with the chin, pure opaque white. 

 Lower part of neck all round, and the entire upper parts, with upper portion of sides, chestnut red. Under parts generally 

 lustrous grayish white, with an occasional brownish tinge ; crissum pure white ; wings brown, without speculum, finely and 

 almost inappreciably sprinkled with gray ; tail nearly black. 



Female with the entire upper parts dark brown ; the back and wing coverts finely sprinkled with grayish. Tlie under parts 

 brownish white, tinged with greenish brown across the lower part of neck. The brown of the head comes down below the 

 level of the eye, and there is an obscure dusky stripe parallel with its lower outline, from the commissure. 

 Length, 16.00 ; wirg, 5.80 ; tarsus, 1.26 ; commissure, 1.80. 

 Hab. — Whole of North America. Abundant throughout the interior. 



The continuity of the white of the under parts is interrupted by the occasional aj)pearance 

 of the basal brown of the feathers, owing to the shortness of the white tip, which thus gives rise 

 to the appearance of dusky transverse bands. 



