BIRDS — FULIGULINAE — BUCEPHALA. 



795 



Female with the black and chestnut replaced by brown, the cheeks and chin lighter, and some tinged with dull rufous. 

 Length, 20.10; wing, 9.30 ; tarsus, 1.70; commissure, 2.65. 

 Hab. — Whole of North America. 



BUCEPHALA, Baird. 



Clangula, Fleming, Philos. Zool. 1828. Type Mnas elangula, L. Not of 1822, which has ^nas glaeialis for type, 



according to G. R. Gray. 

 Glaucion, Kaup, Ent. Europ. Thierw. 1829. Not of Oken, 1816, MoUusca. 

 Bucephala, Baird. Type .dnas albevla, L. 



Ch. — Bill from feathers of forehead about equal to the tarsus and shorter than the head; high at the base; lateral outlines 

 tapering to the tip, where the nail forms only the central portion, though rather large. Nostrils situated near the middle ot 

 the bill. Feathers of chin and forehead extending only moderately foreward a little further than those of cheeks. Tarsus 

 rather more than half the foot. Tail moderately long, about half the wing, and somewhat pointed; of sixteen feathers. 



The B. americana differs decidedly from the B. albeola in a stouter bill, with the nostrils in 

 the posterior portion of the anterior half, instead of in the anterior portion of the posterior part. 



As the genus Olangula of 1822 has Anas glaeialis for type, according to Gray, it cannot he 

 used for the present group. Glaucion of Kaup being pre-occupied, a new name appears to be 

 required. 



The following diagnoses will distinguish the species : 



Common characters. — Head and upper part of neck dark colored, with varied reflections, 

 usually of green, purple, or violet. Lower part of neck all round, under parts and sides, 

 scapulars, middle and greater coverts, and many secondaries, white ; the scapulars .edged 

 externally with black ; upper parts generally black. Inside of wings and axillars sooty. 



An oval patch of white in front of the eye and along the side of the hill, but not 

 reaching its upper corner. White of wings continuous. Head with green reflections. 



Inside of wings and axillars entirely dusky B. americana. 



A triangular patch in front of the eye, applied against the entire base of the bill, and 

 running up in a sharp point. White of wing coverts crossed by a black bar. Head 

 glossed with violet reflections. Inside of wings and axillars pure sooty... B. islandica. 

 A broad white patch on each side the head, behind the eye, and confluent with its fellow 

 on the nape. White of wings continuous. Head glossed anteriorly and behind with 

 green ; between this, with purple violet. Under wing coverts and axillars tipped with 

 white , B. albeola' 



