BIRDS — ANATINAE — ANAS. 



773 



Comparative measurements of species. 



ANAS, Linnaeus. 



^nas, Linnaeus, Syst. Nat. 1735. Type .^nos boschas, L. (Gray.) 



Ch Bill longer than the head or the foot, broad, depressed ; the edges parallel to near the end, which is somewhat acute. 



Nail less than one-third the width of the bill. Nostrils reaching to end of the basal two-fifths of the commissure. Feathers of fore- 

 head,|chiu, and cheeks, reaching about the same point; upper angle of bill about in line with the lower. Tail pointed, about two- 

 fifths the wing. 



The genus Anas embraces very large species, among them the original of the domestic duck. 

 The characters of the two North American species are as follows : 



A. Ends of greater wing coverts white, tipped with black ; speculum purplish violet, termi- 

 nated with black. 



Head and neck green, succeeded by a white ring. Breast dark chestnut. Under parts and 

 scapulars gray, finely undulated with dusky. Tail white, the coverts black.. -4. boschas. 



B, Wing black, the speculum purplish violet, tipped with black. 



Entirely dusky ; the head and neck brownish yellow, spotted with dark brown, which is 

 uniform on the top of head and nape ; sides of nape with a greenish gloss. No white 

 anywhere except on the axillars and inside of wing A. obscura. 



