FORMICARIUS. 75 



being darker on the breast and abdomen and in bavino- the 

 feathers of tbe cheeks, chin, and throat ti))ped with black. 



The description of the immature female is based on an example 

 collected on the Supenaam River, 1910. 



According to Dr. Sclater (Catalogue of the Birds in the 

 British Museum, xv. p. 302) the female is similar to the male 

 and the young have the lores and throat varied with whitish, I 

 am of opinion, however, that this is not the case. The fully adult 

 female, I believe, is distinguished by its white lores, entire white 

 throat, and more or less white on the abdomen. 



The young males have the lores and throat rufous (never white). 

 The young females, on the other hand, never have the lores rufous 

 Ijut always white, and the feathers of the entire tiiroat tipped with 

 white. Whether the throat is entirely black in the first plumage 

 is a problem that the present series, though fairly large, do not 

 enable me to solve. 



Breeding-season. Unknown in British Guiana. 



Nest. Unrecorded in British Guiana. 



Eggs. Undescribed from British Guiana. 



Range in British Gtnaiia. Upper Takutu Mountains, Ituribisi 

 River, Supenaam River, Bartica, Kamakabra River, Makauria 

 River, Lower Mazaruni River, Abary River {McConnell collec- 

 tion) ; Demerara (Brown) ; Kamarang River, Bartica, Kamakusa 

 (Whiteli/). 



Extralimital Range. Surinam {Penarcl), Cayenne (Boddaert), 

 Venezuela, Colombia, Ecuador, Peru. 



Habits. Schomburgk states (Reis. Gukin. iii, p. 6SG) that he 

 found this species in the woods up to an altitude of 4000 feet. It 

 lives almost exclusively on the ground and feeds on insects, 

 caterpillars, etc. Its note, which it utters from time to time, is a 

 peculiar whistling noise. It is often observed following the armies 

 of " Wander- Ants.'' The " Warraus " call it Hehalcatinerarub. 



300. Formicarius crissalis. 

 Rufous-vented Ant-Tiiuush. 



Myiolhera analis (ncc d'Orb.), Cab. in Scliuuil). liois. Cluiuii. iii. n (ISO 



18 IS. 

 3Ii/r)nornis crissalis Cub. J. f. O. ISdl, j). 00 (Uoraima). 

 Funnicarius huJJ'inuiini Sulvin (noc Cab.), Ibis, iSyiJ, p. l^O (Camucusa). 



