CONOPOPHAGIDAE 489 



round spots on both wing and tail ; while the yellowish lower parts 

 of Myrmotlierula pygmaea, Herpsilochmus rufimarginatus and three 

 species of Terenura exhibit the brightest tints found in the Family. 

 Black or dark-hued caps are not infrequent ; crests occur in Batara, 

 Fithys, and many members of Thamnophilus ; the rump-feathers 

 are often dense and elongated, as in Thaninistes, Pygoptila, 

 Chamaeza, Cercomacra, and Thamnomanes ; those of the flanks are 

 much developed in Thamnocliaris ; those of the lores are short 

 and erect in Pyriglena. Bare red or bluish orbits are found occa- 

 sionally ; Gymnocichla has most of the head naked and blue ; and 

 the irides may be red, white, or brown. Batara is quite fourteen 

 inches long, Myrmotherula jpygmaea about three. 



The usually shy and retiring Formicariidae either skulk among 

 dense undergrowth in hot tropical forests, or frequent more culti- 

 vated districts ; they creep about silently, singly or in pairs, seek- 

 ing spiders, insects and their larvae, on the twigs and foliage of 

 trees, or on parasitical plants or grasses; while they habitually keep 

 near the ground, though sometimes joining flocks of other birds 

 in their higher flights. Many carefully search the lower surface of 

 the leaves for food with the head downwards, and occasionally eat 

 seeds. The Grallariinae appear to be entirely, and the Formi- 

 eariinae to a great extent terrestrial, hops being the characteristic 

 mode of progress ; the tail is commonly carried erect or in motion, 

 as in the case of Formicarius, and is often much abraded by 

 the thorny thickets. Thamnophilus albinuchalis and some other 

 species choose dry situations, but generally the vicinity of water 

 is preferred. The ordinary note in the Family is deep and 

 powerful, and is said to have the effect of ventriloquism ; it con- 

 sists of monotonously repeated sounds, like ke-ke-ke or ko-ko-ko, 

 varied by more rasping tones or trills. The nest, a slight shallow 

 structure, generally hung from the lower twigs of a tree or bush, is 

 composed of straws, fibres, roots, and hair, or occasionally of leaves, 

 moss, and wool ; it contains two or three white, bluish, or rufous- 

 brown eggs, usually spotted, streaked, or zigzagged with red-brown, 

 but more rarely with grey. 



Fam. XL Oonopophagidae. — These curious birds, and their 

 equally remarkable allies the Fteroptochidae, differ from all other 

 Passeres in having two incisions posteriorly on each side of the 

 sternum. The Oonopophagidae, extending from Colombia to Bolivia 

 and Brazil, include the genus Conopophaga and probably Coryth- 



