50 BIEDB OF BRITISH GUIANA. 



Adult male. General colour above dark chocolate-bro-wn, some- 

 what richer and inclining to deep chestnut-brown on the head ; 

 the base o£ the feathers on the mantle pure white, which forms 

 a semi-obscured dorsal patch; inner webs of the primary and 

 secondary quills blackish with pale fulvous inner margins ; tail 

 similar to the back but somewhat paler ; cheeks and ear-coverts 

 deep chestnut, rather darker on the hinder portion of the latter ; 

 fore-neck and throat fawn-colour, richer and deeper in colour on 

 the latter like the outer edge of the wing ; breast, abdomen, under 

 tail-coverts, sides of body, and inner under wing-coverts dusky 

 fawn-brown. 



Total length 136 mm., exposed culmen 16, wing 76, tail 47, 

 tarsus 27. 



Adult female. Similar in the general colour of the plumage to 

 the adult male, but differs in having the dorsal patch orange-buff 

 instead of pure white. Wing 75 mm. 



The birds from which the descriptions are taken were collected 

 on the Ituribisi River in February 1907. 



A nestling in the British Museum, collected by Whitely at 

 Bartica in January 1880, is uniform chocolate-brown both above 

 and below. 



Breeding-season. June (^Beebe). 



Nest. Built of small twigs and vine stems lined with a few 

 pieces of coarse fibre (Beebe) . 



Sggs. Warm pinkish ground-colour, marked with purplish 

 red, lilac and lake, chiefly at the larger end : measurements 

 21-5 X 17 mm. (Beebe). 



Range in British. Guiana. Ituribisi River, Bartica, Makauria 

 River (McConnell collection); Kamakusa, Bartica {WJiitely); 

 Maccasseema ( W. L. Sclater). 



Extralimital Range. Surinam (Penard), Cayenne (Boddaert), 

 North-east Brazil. 



Habits. Schomburgk states (Reis. Guian. iii. p. 685) that he 

 only found this bird in the low brush of the coast- woods or on 

 tlie ground in search for its food. 



The following note is copied from W. L. Sclater (Ibis, 1887, 

 p. 318) : — "This Ant-Thrush, I was told, was commonly known 

 as the Yackman-bird. It is said to be seen only in pursuit of the 

 moving troops of the Yackman-ants {Eaton, sp. inc.), which, as 

 is stated, have no nest, bat move in enormous masses through the 



