578 PATAGONIAN EXPEDITIONS ! ZOOLOGY. 



IBYCTER CIRCUMCINCTUS Scott. 

 Ibycter circumcinctus Scott, Auk, XXVII, p. 152, 1910. 



Type. Princeton University Collection, 8993. Adult male. Chubut, 

 Patagonia, February, 1896. Collected by the Museo de la Plata. (Orig- 

 inal Number 8; exchange with Princeton University.) 



Size. Male cited. 



Total length, about 24 inches. 



Wing, 16.25 inches. 



Oilmen, from in front of cere, 1.30. Cere at forehead, 0.40. 



Tail, 10.30 inches. 



Tarsus, 2.55 inches. 



Color. General color : Black and white. Black preponderating above ; 

 white prevailing below. 



Head : Black with lanceolate feathers, prolonged on the occiput into a 

 decided occipital crest ; undershading throughout deep brown. 



Neck: Black above and on the sides, with deep brown undershade. 

 Chin and upper neck below pure white ; this is divided from the white 

 lower neck by a black band, more or less variegated with white markings 

 on some of the feathers ; this band is an inch and a half wide. Lower 

 neck white, with the black of the sides confining it to a narrow strip, which 

 widens on the upper breast. 



Back : Mantle and lower back black with a dull green gloss and under- 

 shade of deep brown. Rump and upper tail-coverts pure white. 



Tail : The base definitely white, the rectrices here having ivory-white 

 shafts ; thence black prevails for six inches and the shafts of the rectrices 

 are shining black ; a terminal pure white band about an inch and a half 

 broad, and here the shafts of the rectrices are again ivory-white. Below, 

 the tail is duller, but presents the same pattern. 



Wings : Above black, with a dull brown undertone, obscure and green 

 reflections; the quills black, both the primaries and secondaries tipped 

 with white. Small plumes along bend of wing conspicuously white, when 

 wing is closed ; the feathers of the border of the shoulders first white, then 

 chiefly black, with an admixture of white, and finally wholly black. 



Under parts : The chin and throat white, separated from the white of 

 the breast by a broad black band, somewhat variegated with white mark- 

 ings, irregular in shape and size, on some of the feathers. The white on 

 the lower throat is confined to a narrow strip in the center, bounded by 



