NETTIUM. 441 



forming a speculum ; smaller wing-coverts brown, median chestnut, 

 greater velvety black ; wing-lining and lower parts white, the upper 

 breast with crescentic brown bars, sides and flanks with narrow- 

 wavy brown bars ; lower abdomen with dusky markings ; under 

 tail-coverts black. After the breeding-season the drake assumes 

 female plumage. 



Female. Head and neck streaked brown and white, brown pre- 

 dominating above, white beneath ; upper parts dark brown, with 

 rufous-buff edges to feathers ; rump blacker ; wings as in the 

 male, except that the chestnut is wanting or confined to a few of 

 the median wing-coverts ; breast pale rufous, spotted with brown ; 

 abdomen white. In young birds the lower parts are spotted 

 throughout. 



Bill in male black or brownish, reddish or yellow on the 

 lower mandible; in female brownish orange, blackish on the 

 tip and culm en ; irides brown ; legs yellowish brown to dull 

 orange. 



Length of male 20 ; tail 3-4 ; wing 10 -5 ; tarsus 1*5 ; bill from 

 gape 2-1. Females are smaller : wing 9'5. 



Distribution. Throughout the greater part of the northern hemi- 

 sphere, breeding in the temperate zone and migrating in winter 

 to the southward. The Gadwall is common from October to 

 March throughout Northern India, from the Punjab and Sind to 

 Assam, Manipur,and in Upper Burma; but it has not been observed 

 in Pegu or Tenasserim, nor in the Peninsula of India south of 

 Mysore, nor in Ceylon. 



Habits, fyc. Gadwalls are common Ducks in Northern India, 

 and may be found in small or large flocks wherever there are 

 rivers, tanks, or marshes, but they do not in general resort to the 

 sea-coast. Their call and food are very similar to those of the 

 Mallard, and their flight is rather more rapid. They are not known 

 to breed within our limits. As a rule they are good to eat. 



Genus NETTIUM, Kaup, 1829. 



This genus, containing the Common Teal and some allied species, 

 differs from Anas in having a smaller number of tail-feathers, 

 14 or 16 as a rule, in the narrower bill, and in the smaller size of 

 the birds. The differences from Chauldasmus and Mareca are 

 also slight. 



Key to the Species. 



a. Sexes different in plumage. 



a' . Secondaries bronze-green near coverts, black 



towards ends N. formosum, p. 442. 



b'. Outer secondaries black, inner green N. crecca, p. 443. 



b. Sexes alike. 



c. Outer web of 1st secondary white > of 7th-9th 



bronze, of others black " N. albigulare, p. 444. 



