ANATID^E THE SWANS, GEESE, AND DUCKS. 127 



SUBGENUS ANAS LINN.EUS. 



Anas LINN. S. N. ed. 10, i, 1758, 122; ed. 12, i, 1766, 194. Type, by elimination, A. bos- 

 chas LINN. 



SUBGEN. CHAK. Usually rather large-sized ducks (wing, in North American species, 

 10 inches or more), with the bill a little longer than the head or foot, rather broad, de- 

 pressed, the edges parallel, the end rounded; speculum metallic green, blue, or violet, 

 in both sexes, usually bordered posteriorly by a black band, this generally succeeded 

 by a white one. 



The two species which are known to occur in Illinois are 

 characterized as follows: 



A. Adult male, except in breeding season, very different from the female, the plumage 

 varied and brilliant; secondaries tipped with white, and greater coverts crossed by a 

 subterrninal bar of the same. 



1. A. boschas. Adult male: Pour middle tail-feathers strongly recurved; head and 

 neck brilliant velvety green; chest rich chestnut, with a white collar between it 

 and the green of the neck; speculum rich metallic violet, bounded anteriorly by a 

 black bar, this preceded by a white one, and posteriorly by a black subterrninal 

 and white terminal band. Adult female and mal' in breeding seafon: Wings 

 as in the above; elsewhere variegated with dusky and ochraceous, the former 

 on the centres of the feathers, and predominating on the upper parts, the latter 

 on the borders, and prevailing beneath. 



B. Sexes alike, at all ages and seasons; no white on the outer surface of the wing. 



2. A. obscura. Prevailing color dusky, the feathers bordered with dull ochraceous; 

 head and neck dull buff, everywhere streaked with dusky; no black at base of 

 the bill; speculum usually .deep violet. 



Anas boschas Linn. 



MALLAED. 



Popular synonyms. Green-head; Wild Drake; Wild Duck; English Duck (Florida); 

 French Duck (Louisiana); Gray Duck; Gray Mallard. 



Anas boschas LINN. S. N. eel, 10, i, 1758, 127; ed. 12, i. 1766, 205. WILS. Am. Orn. viii, 

 1814, 112, pi. 70, f, 7. AUD. Orn. Biog. iii, 1835, 164, pi. 221; Synop. 1839, 276; B. 

 Am. vi, 1813, 236, pi, 385. BAIED. B. N. Am. 1858, 774; Cat. N. Am. B. 1859, No. 576. 

 COUES, Key, 1872, 285; Check List, 1873. 488; B. N. W. 1874, 559. -B. B. & R. Water 

 B. N. Am. i, 1884, 491. HENSH. Zool. Wheeler's Exp. 1875, 472. A. O. U. Check 

 List, 1886, No. 132. RIDGW. Oru. 40th Par. 1877, 621; Man. N. Am. B. 1887, 91. 

 Anas boscas WHAETON, Ibis, 1879, 453. RIDGW. Nom. N. Am, B. 1881, No. 601. COUES, 

 Check List, 2d ed. 1882, No. 707. 



Anas domestica GMEL. S. N. i, pt. ii, 1788, 538. 



Anas (Eochas) domestica Sw. & RICH. F. B.-A. ii, 1831, 442. NUTT Man. ii, 1834, 378. 



Anas fera "BBiss." LEACH, Cat. Brit. Mus. 1816, 30. 



Anas adunca LINN. S. N. ed. 12, i, 1766, 206. GMEL. S. N. i, pt. ii, 1788, 538. 



HAB. Northern hemisphere; in North America, generally distributed, migrating 

 south in winter to Panama, Cuba, and Bahamas. 



SP. CHAK. Adult male in fall, winter, and spring: Head and neck continuous soft bril- 

 liant metallic green, showing purple and golden-bronze reflections in different lights. 

 A ring of pure white round the lower part of the neck interrupted behind; chest and 



