134 BIRDS OF ILLINOIS. 



Total length (adult), about 15.50-16.50 inches; extent, 24.00-24.50; wing, 7.20-7.75; cul- 

 men, 1.65-1.85; tarsus, 1.25-1.35; middle toe, 1.40-1.50. 



Examples from Chili and the Argentine Republic are larger and 

 more richly colored than those from the United States ; the white 

 bar across the end of the middle coverts narrower, and nearly con- 

 cealed by the overlying last row of lesser coverts. The differ- 

 ences, however, may not prove constant. 



The female of this species is very difficult to distinguish from 

 that of A. discors, and it is probably not possible always to 

 separate them with certainty. The present species averages 

 considerably larger, however; the wings in the adult female 

 ranging from 7.20 to 7.50 inches, the culmen 1.70 to 1.75, 

 against 6.70 to 7.00, and 1.40 to 1.50, as in A. discors. The 

 colors are also deeper, nearly the whole throat being streaked, 

 the breast deeply tinged with light brown, and the abdomen 

 almost always distinctly spotted. 



This western representation of the Blue-winged Teal, is com- 

 mon as far east as middle Kansas, where, according to Col. N. 

 S. Goss, it probabty breeds, but nearer the Mississippi River it 

 is of irregular and uncertain occurrence, having been only once 

 or twice taken in Illinois. 



Its habits are very similar to those of the Blue-wing. 



SUBGENUS Nettion Kaup. 



Nettion KAUP, Entw. Eur. Thierw. 1829, 95, 196. Type, Anas crecca LINN. 



SUBGEN. CHAK. Bill shorter than head, narrow, depressed (except at base), the edges 

 parallel; tarsus shorter than bill or middle toe; nape with a small mane-like tuft; rec- 

 trices more or less acuminate, the middle pair longest. 



This subgenus is very readily distinguished from Querquedula 

 by the conspicuously different form of the bill, which is far more 

 like that of Dafila, though much smaller, being conspicuously more 

 depressed terminally and proportionally deeper through the base 

 than in Querquedula, while the lower edge or maxillary tomium 

 is either gently convex throughout (as in the southern species), 

 or straight anteriorly and decidedly convex posteriorly (as in 

 the northern forms), the lamellae being thus completely hidden. 

 In Qn<-r<ji'lnfit, on the other hand, the terminal portion of the 

 tomium is strongly convex, and the posterior half cut away, as 



