130 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I50 



10. Tail elongated, with the feathers sharply pointed; wing speculum green in 



male ; gray in female Pintail, Anas acuta, p. 140 



Tail rounded ; wing speculum deep, shining blue in both sexes. 



Mallard, Anas p. platyrhynchos, p. 139 



11. A prominent white crescent on forepart of head in front of eye. 



Blue-winged teal, Anas discors, male, p. 141 

 No white mark on forepart of head 12 



12. Plumage cinnamon or chestnut brown, above and below. 



Cinnamon teal. Anas cyanoptera septentrionalium, adult male, p. 144 



Blackish above edged with buffy white, lighter below, mottled in appearance 



throughout 13 



13. Bill slightly smaller, 37-41 mm. long. 



Blue-winged teal. Anas discors, female, p. 141 

 Bill slightly heavier, 41-44 mm. long. 



Cinnamon teal. Anas cyanoptera septentrionalium, female, p. 144 



14. Smaller, wing less than 150 mm. ; tail longer, with narrowed feathers, the 



extended feet not reaching to its end. 



Masked duck, Oxyura dominica, p. 150 



Larger, wing more than 175 mm.; tail shorter, with broader feathers, the 



extended feet reaching to its end 15 



15. Wing speculum white Lesser scaup duck, Aythya affinis, p. 148 



Wing speculum gray Ring-necked duck, Aythya collaris, p. 150 



DENDROCYGNA VIDUATA (Linnaeus): White-faced Tree Duck; Jacamillo 



Anas viduata Linnaeus, Syst. Nat., ed. 12, vol. 1, 1766, p. 205. (Cartagena, 

 Colombia.) 



Forepart of head white ; sides black barred with white. 



Description. — Length 380 to 430 mm. Head white to behind level 

 of eyes; posterior area of head, sides of neck, center of breast, 

 abdomen, lower back, wings, and tail black ; f oreneck white in some, 

 or black with a spot of white in the center in others ; a brown band 

 around lower neck, upper breast, and upper back ; sides buffy white 

 barred with black ; upper back fuscous lined with buff. 



Iris brown ; bill black ; tarsus bluish gray ; toes darker ; claws black. 



Measurements. — Males (4 from Venezuela, Brazil, Paraguay, and 

 Argentina), wing 206-229 (218), tail 56.5-63.4 (60.7), culmen from 

 base 47.0-49.0 (48.0), tarsus 49.5-56.7 (54.3) mm. 



Females (4 from Panama, Venezuela, and Argentina), wing 207- 

 228 (215), tail 60.5-64.4 (62.2), culmen from base 43.8-49.3 (46.6), 

 tarsus 49.8-53.7 (51.7) mm. 



Resident. Formerly fairly common, now rare; recorded from the 

 Canal Zone, and from the marshes near the Rio Pacora and the Rio 

 La Jagua. 



Little is known regarding this species in Panama. Griscom (Bull. 

 Mus. Comp. Zool., vol. 78, 1935, p. 296) records it with the statement 

 "Canal Zone (1 shot)," without further detail. There are two sped- 



