ANAS. 91 



Above olivaceous, relieved by two pairs of j^ellowish spots, 

 one pair on the back, just behind the wings, the other on 

 each side of the base of the tail ; lower parts, including 

 sides of head and broad superciliary stripe, yellowish buff, 

 deepest on head, paler and duller posteriorly ; side of head 

 marked by a narrow but very distinct stripe of dark 

 brown, extending from upper basal angle of the maxilla 

 to the eye, and thence to, and confluent with, the oliva- 

 ceous of the occiput; beneath this stripe an auricular spot 

 of dusky ; sides crossed by two olivaceous patches, con- 

 fluent with the olive of the back. Length about 20.00- 

 25.00, wing 10.25-12.00, culmen 2.00-2.40, tarsus 1.50-1.80, 

 middle toe 1.90-2.15. Eggs 2.32 X 1.67, pale olive-buff, 

 pale greenish buff, or pale buffy pea-green. Hab. Whole of 

 northern hemisphere. 



132. A. boschas LINN. Mallard. 



cP. Smaller wing-coverts distinctly bordered or margined with buff 

 or ochraceous, and tertials edged with same ; sexes alike in 

 plumage. 

 e l . Wing without any white bands. 



f 1 . Cheeks, chin, and entire throat distinctly streaked with 

 dusky ; dusky markings largely predominating in ex- 

 tent over the lighter (buffy or ochraceous) ; lower 

 basal corner of upper mandible without black spot ; 

 speculum usually deep violet. Downy young: Above 

 olive-brown, slightly relieved by three pairs of light 

 dull buff spots, as follows : One on posterior border 

 of arm-wing (this sometimes indistinct), one on sides 

 of back, just behind wing, and one on sides of rump, 

 near base of tail ; top of head and hind-neck olive- 

 brown, like back, etc. ; rest of head and neck, with 

 lower parts, pale dingy buff, paler on belly ; sides of 

 head marked with a narrow dusky streak, from upper 

 basal angle of bill to eye and thence back to occiput ; 

 a dusky auricular spot, continued less distinctly back 

 to nape. Length 21.00-24.50, wing 10.50-11.50, cul- 

 men 2.00-2.35, tarsus 1.70-1.80, middle toe 1.90-2.10. 

 Eggs 2.43 X 1-75, pale dull buff or pale greenish buff. 

 Hab. Eastern North America, breeding from more 

 northern United States to Hudson's Bay, including 

 whole of Labrador. (Western and southern limits 

 imperfectly determined.) 



133. A. obscura GMEL. Black Duck. 



/*. Cheeks, chin, and throat plain buff; ochraceous or buff 

 markings predominating in extent over the darker 



