272 BROOKLYN INSTITUTE MUSEUM. SCIENCE BULLETIN 2. 6. 



g'. Under parts not white. 



h. General color of under parts slate gray d'Dysithaninus ardesiacus ar- 



desiacus. 

 h'. General color of under parts ochraceous buff (it may be 

 clear or dusky). 

 i. Upper parts bright hazel brown, or olive brown. 



j. Hazel brown above 9 Thamnophilus dolialus. 



j'. Olive brown above 9 Dysiihamnus ardesiacus sal- 



urninus. 



i'. Upper parts slate color dTygiplila steUaris. 



/'. Wing not more than 65 mm. 



g. Genera! color above gray (slate gray or olive gray) . 



h. Middle of belly pale yellowish d^ Dysiihamnus affinis andrei. 



h'. Middle of belly pale grayish (whitish) d'Tliamnophilus murinus. 



g'. General color above olive or olive brown and crown and 

 occiput tawny olive. 

 h. Larger, tail | as long as wing or more; under parts 



pale buffy brownish 9 Thamnophilus murinus. 



h'. Smaller, tail less than f as long as wing; under parts 



pale grayish ; buffy yellowish on crissum 9 Dysiihamnus affinis andrei. 



e'. Wing coverts with distinct white or buffy tips, or other pale 

 wing markings. 



/. General color below white (immaculate) ; above black d'Taraba major albicrissa. 



f. General color below not immaculate white. 



g. Head all round and throat black (fHypolophus canadensis Irin- 



iiaiis. 

 g'. .Sides of head and throat not black. 



h. General color of under parts a uniform gray (in shade 

 varying from pale neutral gray to slate gray). 

 i. Tertials and inner secondaries edged or tipped, or 

 both, with white or pale gray. 

 ,;'. Crown and occiput black. 



k. Primary coverts narrowly tipped with white .... Erionolus naevius naevius. 



k'. Primary coverts not tipped with white Erionolus insignis. ' 



j'. Crown and occiput slate gray or gray mixed with 



hazel brown ( c? im) d^ and cf im. Erionohis cine- 



reiceps. 

 i'. Tertials and inner secondaries not tipped and edged 

 (on outer webs) with white or pale grayish. 

 j. Nearly uniform slate grayish above, no black on 

 crown, wing-coverts with very small whitish apical 



spots d'Thamnophihis murinus. 



j'. Crown and nape black (and more or less black on 



the interscapulars) dTygiplila stellaris. 



h'. General color of under parts not uniform grayish. 

 i. Chin, throat, and upper breast bright tawny ochrace- 

 ous 9 Thamnophilus amazonicus. 



i'. Under parts in general a uniform pale buff or tawny 

 ochraceous; or striated with white on a gray ground, 

 or buffy brownish on a grayish white ground. 

 j. Tail cinnamon brown. 



k. White tip to tail-feathers confined to inner web 

 except on two outermost rectrices (outer face 

 of posterior half of tarsus with more or less oval 



scutes not closely joined to one another) 9 or cT (im) Erionolus in- 

 signis. 

 k'. White tips to rectrices larger and not confined to 

 inner webs of quills (outer face of posterior half 

 of tarsus with nearly quadrangular scutes unit- 

 ing with those from the opposite side in a sharp 



ridge) 9 Erionolus naevius naevius. 



j'. Tail black or blackish brown. 



k. With an occipital crest; crown and occiput 



chestnut, sharply different in color from back. . . 9 Hypolophus canadensis trin- 



ilatis. 

 k'. No occipital crest , and color of crown and occiput 

 not different from back. 

 /. Slate gray (deep neutral gray) or slate black 

 above. 

 m. Smaller, wing less than 75 mm.; upper 



parts deep neutral gray cfSclateria argenlala. 



m'. Larger, wing more than 75 mm.; upper 



parts slate black c^Sclaieria schistacea cauren- 



sis. 

 I'. General color above rufescent brown or mum- 

 my brown. 



'I do not know of any records in the immediate Orinoco valley, but there is a good series from Cristobal 

 Colon, Paria Peninsula (American Museum Collection), and as the type comes from British Guiana the 

 species is probably found in intermediate localities. 



