152 Scott, A New Species of Carrion Haivl; [aptU 



AN APPARENTLY NEW SPECIES OF CARRION HAWK 

 OF THE GENUS IBYCTER. 



BY WILLIAM E. D. SCOTT. 



Ibycter circumcinctus spec. nov. 



Type, Princeton University Collection, No. 8993, adult male, Chubut, 

 Territory of Chubut, Patagonia. 



Size. Total length, about 24 inches; wing, 16.25 inches; tail, 10.30 

 inches; tarsus, 2.55 inches; culmen from front of cere, 1.30 inches; cere 

 to forehead, 0.40 inch. 



Color. General color black and white; black prevailing above, white 

 prevailing beneath. 



Forehead, lores, sides of head and crown deep velvety black; the 

 feathers of the entire crown and top of head lanceolate and prolonged into 

 a recurved crest on the occiput. Neck concolor with head on the top and 

 sides; throat pure white; the black of the sides of the neck joined by a 

 band of black below the white throat patch; the feathers of this band are 

 not all pure black but some of them have one web largely encroached upon 

 by white ; the effect is a band of black below the throat patch more or less 

 variegated by white on some of the feathers; this band is about an inch in 

 width; lower part of the under neck pure white, the black of the sides of 

 the neck confining the white of this region to a narrow area, widening into 

 the pure white of the breast. Mantle and lower back black with a dull 

 green gloss and some shading of deep brown; rump and upper tail-coverts 

 pure white. Tail, base definitely white, the rectrices here having ivory 

 white shafts; thence black prevails for seven inches, the shafts being 

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

 where the shafts of the rectrices are again ivory white. Seen from below 

 the tail presents the same pattern, the colors all being duller. Wings 

 above black with a dull undertone of deep brown and with dull green 

 reflections glossing the darker shades; the vipper wing-coverts as above 

 except that the small feathers along the bend of the wing are in strong 

 contrast, pure white; this feature is marked and when the wing is closed 

 a half inch or more of white borders the radial portion of the bend; 

 quills all black with a deep brown tone, both the primaries and secondaries 

 being conspicuously tipped with pure white. Under wing-coverts and 

 axillaries pure white. Lower parts. Chin and throat pure white, sepa- 

 rated from the immaculate white of the breast by a broad band somewhat 

 variegated with white markings on some feathers. The white on the 

 lower throat is confined to the center, bounded by black on either side and 

 widening to three inches on the upper breast, the black border reaching 



