N.W. Argentina and the Bolivian Ckuco. 463 



the posterior end of the culmen, and thus a good deal in 

 front of the eye. General colour of the mantle and the 

 wing-coverts dark, almost blackish grey, with a rather 

 strong greenish-olive tinge in some lights. All feathers 

 with a black median shaft-line, and finely mottled with 

 numerous minute dots of yellowish, more ochraceous 

 on the mantle, more whitish on the wing-coverts. This 

 same mottling and general colour extends also over the 

 scapulars and the outer web of the proximal secondaries. 

 Secondaries otherwise dark slaty, with a brownish 

 tinge on the outer edges. Primaries darker slaty with a 

 bluish tinge, and fringed with white at the tips. Bastard- 

 wing and large primary-coverts similar (but without any 

 white bars as in Heterocnus cabanisi). Bend of the wing 

 white, with a buffy tinge and with brown spots on the inner 

 web of the feather. Crown of the head black ; occipital 

 crest chestnut-red, with black tips to some of the feathers. 

 The whole of the amply-frilled hind-neck and sides of 

 the neck uniform chestnut-red. Lores and orbits naked, 

 a narrow black stripe separating the bare area from the 

 chestnut-red ear-coverts and sides of the nape. This black 

 band extends down the sides of the bare throat, but is there 

 streaked with white. A white feather-band extends forward 

 in the middle of the otherwise bare throat, as has been stated 

 above. This white stripe continues down the middle of the 

 fore-neck, bordered on each side by the narrow black band ; 

 further down it becomes broadly spotted with brown and 

 black. Thus the middle of the fore-neck has a brown-and- 

 black central baud bordered on each side by a white hand, 

 and that again by a narrow black stripe separated from the 

 chestnut-red sides of the neck. The lowermost part of 

 the fore-neck is more irregularly and broadly spotted or 

 rather striped with black, white, and chestnut. Breast 

 slaty grey, with a rufous tinge on the ends of the feathers. 

 Abdomen light, and under tail-coverts dusky cinereous, 

 flanks and axillaries dark slaty, with narrow white wavy 

 cross - bands. ruder wing - coverts similar, except the 

 smallest, which have the same coloration as the upper 



