158 Proceedings of the Biological Society of Washington. 



2. Two outer tail feathers uniform brownish rufous; third tail 

 feather with blackish border on inner web ; under parts rufous 

 cinnamon; size larger, wing about 72 mm. 



Cranioleuca? graminicola (Sclater).* 

 (Near Junin, Peru.) 

 b 2 . Outer tail feathers largely dark brown (not uniform rufous or 

 brownish rufous) ; under parts buffy white. 



1 . Bill shorter ; exposed edges of basal part of inner primaries not 



rufous; inner tail feathers blacker and the pale edging not so 

 pronounced; throat patch larger; darker rufous wing (about 

 70 mm.) Cranioleuca humilis humilis (Cabanis). 



(Junin, Peru.) 



2. Bill longer; exposed edge of basal part of inner primaries rufous; 



pale edging on inner tail feathers brighter and more conspicu- 

 ous; throat patch smaller; paler rufous wing (about 67) 

 Cranioleuca humilis marayniocensis (Berlepsch and Stolzmann). 



(Maraynioc, C. Peru.) 



3. Similar but larger; wing about 74 mm. 



Cranioleuca humilis robusta (Berlepsch). 



(Iquico, W. Bolivia.) 



b 1 . Upper parts olive buffy or olivaceous tawny streaked with blackish. 



b 2 . Cap plain bright rufous; size smaller, wing less than 55 mm.; 



tail attenuated and sharply pointed 



Siptornoides (Eusiptornoides maluroides (d'Orbigny and Lafresnaye). 



(Buenos Aires, Argentina.) 

 c 2 . Cap not plain rufous; whole crown streaked; size larger, wing 

 much more than 60 mm. ; tail attenuated and pointed. 

 c 3 . Superciliary stripe whitish or buffy white. 



1. Throat spot rufous ;| flanks and under tail coverts not dis- 



tinctly streaked; smaller, wing 70 mm. or less 



Siptornoides (Eusiptornoides) anthoides (King). 



(Straits of Magellan.) 



2. Throat spot yellowish or rufous; flanks and under tail cov- 



erts more or less streaked; wing about 74 mm. 



Siptornoides (Eusiptornoides) hudsoni (Sclater). 

 (Conchitas, Buenos Aires, Argentina.) 



3. Throat spot rufous; lower abdomen and flanks uniform fawn 



color without streaks; size of hudsoni 



Siptornoides (Eusiptornoides) lilloi (Oustalet).J 



(Tucuman, Argentina). 



* I have not seen graminicola Sclater and it may belong to a different genus. 



t The gular patch and general color of the throat is very variable and may be due to 

 age. In this connection Mr. Charles Chubb writes me as follows: "The colour of the throat 

 is a variable character which occurs in both male and female being sometimes white dotted 

 with black, at others lemon or sulphur yellow, and many (at all seasons of the year) cin- 

 namon rufous." 



t I have not seen specimens of either lilloi or punensis. 



