194 FORMICARIIDZA. 
some mahogany colour with darker shades of the same (Cercomacra), while Grallaria 
lays rich dark greenish-blue eggs, very different, apparently, from the others. 
All the species feed on insects, which they capture amongst the foliage or branches 
of trees or pick from amongst the fallen débris on the ground. The statement that 
the food of many species of Formicariide consists largely of ants, is open to question, 
and the late Thomas Belt, we think, satisfactorily explains how this observation has 
arisen. In writing of the habits of the various species of Hciton found in Nicaragua 
(‘The Naturalist in Nicaragua,’ p. 20) he says:—‘ Several species of Ant-Thrushes 
(i. e. Formicariide) always accompany the army ants in the forest. They do not, how- 
ever, feed on the ants, but on the insects they disturb. Besides the Ant-Thrushes, 
Trogons, Creepers, and a variety of other birds are often seen in the branches of trees 
above where an ant army is foraging below, pursuing and catching the insects as they 
fly up.” 
A. Arboricole: tarsi plerumque breves. 
a. Nares omnino aperte, rostrum quam caput vix longior. 
a’. Vibrisse vix obvie, tarsi undique scutellati. 
al, Rostrum robustum, valde hamatum. 
al”. Rostrum minime compressum. 
CYMBILANIUS. 
Cymbilanius, Gray, List Gen. Birds, p. 86 (1840) ; Scl. Cat. Birds Brit. Mus. xv. p. 178. 
This genus contains a single species, distinguished by its comparatively short, thick, 
tumid bill, which is wider at the base than that of Thamnophilus and not compressed ; 
the terminal hook of the maxilla is very pronounced, and is preceded by a very deep 
notch, the rest of the tomia being nearly straight ; the mandible has also a well-marked 
notch near the end and a wide indentation in the tomia just before it. The culmen 
curves slightly from the base until it descends rapidly to form the terminal hook; the 
gonys ascends rather abruptly. The nostrils are quite open, slightly oval, the frontal 
feathers just reaching the proximal end of the opening. The tarsi are covered, both in 
front and behind, with well-defined scutella; the claws are short, strongly curved, and 
compressed. ‘The distribution of the genus is that of the species which follows. 
1. Cymbilanius lineatus. 
Lanius lineatus, Leach, Zool. Misc. i. p. 20, t. 6 (1815) ’. 
Cymbilanius lineatus, Gray, List Gen. Birds, p. 36 (1840) *; Lawr. Ann. Lyc. N. Y. vii. p. 293°; 
