ANATIDjE THE SWANS, GEESE, AND DUCKS. 173 



similar to the male, but the head, neck, and chest grayish brown, with a distinct white spot 

 on the auricular region, and the lores and sides of the forehead inclining to white. Chest, 

 sides, flanks, and crissum entirely uniform grayish brown. "Bill and feet dull bluish gray ; 

 iris brown" (AuDUBON). Young. Similar to the adult female, but above browner and more 

 uniform, the chest, sides, flanks, and crissum tinged with umber. 



Total length, about 17.50 Inches; extent, 27.00; wing, 7.40 to nearly 8.00; culmen, 1.05-1.10 ; 

 tarsus, 1.50; middle toe, 2.00. Female slightly smaller. 



The Harlequin Duck is a winter visitant or resident in Illi- 

 nois, but is probably not at any time a common species. In 

 its summer home, which is in more northern or mountainous 

 regions, it frequents swiftly running streams, where it delights 

 to sport among the eddies below water falls or in the brawling 

 rapids. Its nest is often placed in a hollow of a tree, but fre- 

 quently in other situations. 



GENUS CLANGITLA LEACH. 



Clangula LEACH, in Boss's Voy. Disc. 1819, App. p. xlvili. Type, Anas glacialis LINN. 



Harelda LEACH, Steph. Gen. Zool. xli, 1824, 174. Type, Anas glacialis LINN. 



Paaonetta KAUP, EnL Europ. Thierw. 1829, 66. Same type. 



Crymonessa MACQ. Man. Brit. Orn. ii, 1842, 185. Same type. 



Melonetta SUND. Tent 1872, 149. Same type. 



GEN. CHAB. Bill small (much shorter than the tarsus), all Its outlines tapering rapidly 

 to the end, which is occupied entirely by the very large broad nail; lower edge of the max- 

 illa nearly straight for the basal half, then suddenly rising to the prominently decurved 

 nail; lamellae slightly exposed along the straight basal portion of the maxillary tomium; 

 feathering at the base of the bill forming a nearly straight oblique line, advancing farthest 

 forward on the forehead, and scarcely interrupted by any re-entrant angle, so prominent 

 in most ducks. Adult male with the longer scapulars elongated and lanceolate, the rectrices 

 (14 in number) acute, the middle pair slender and greatly lengthened. 



The most important peculiarity of structure in this well- 

 marked genus consists in the almost unique outline of the 

 feathering at the base of the bill, this outline advancing grad- 

 ually farther forward from the rictus to the base of the culmen, 

 the continuity of the slightly curved line interrupted by only a 

 very faint, sometimes scarcely perceptible, indentation at the 

 place of the deep angle seen in most ducks. The only other 

 genus showing an approach to this character is Camptolaimus, 

 which, however, has the bill and other features very different. 



But a single species is known, which, like Histrionieus, is cir- 

 cumpolar in its distribution, but descends to lower latitudes in 

 winter. 



