490 PASSERIFORMES——PTEROPTOCHIDAE CHAP. 
opis. The head is large, the bill depressed in the first-named, 
longer and more compressed in the last; the exaspidean meta- 
tarsus (p. 475) is thick and long in the one, with broad curved hind- 
claw, but is thinner, with straighter and weaker hallux, in the other. 
The outer and middle toes are basally connected. The wings are 
moderate and rounded, as in the next Family ; the tail is very short 
in Conopophaga, which has long, lax rump-feathers. The general 
coloration is brown, with a white mark behind the eye in the last- 
named genus; the head may be black, or chestnut with black sides ; 
the throat black ; the breast banded with chestnut, black or grey ; or 
the central abdomen white. Corythopis has black striations below. 
Fam. XII. Pteroptochidae.—This group ranges from Costa 
Rica to Patagonia, occurring up to an altitude of nine or ten 
thousand feet. The bill is comparatively long and thin in Scyta- 
lopus and Merulaxis, stronger in Liosceles, Pteroptochus, Hylactes, 
and Rhinocrypta, being much arched in the last-named; the 
culmen expands into a peculiar oval plate in Acropternis and Trip- 
torhinus ; while a membrane partially covers the nostrils. The 
taxaspidean metatarsus (p. 471) is generally elongated and strong, 
with long claws, the hallux being long and incurved in Hylactes, 
and similar but straighter in Acropternis; the whole foot is shorter 
in Rhinocrypta, more slender in Pteroptochus, while the scutes are 
fused in front in Liosceles. The short, rounded wings have ten 
primaries and eight secondaries; the tail varies in length, and 
may be graduated, as in Merulaxis and Acropternis, or short and 
more even, as in 7riptorhinus. Hylactes has fourteen rectrices 
in place of twelve. The colour is blackish, dark grey, or brown, 
often barred or scalloped with black; the crown, rump, breast, or 
belly are at times chestnut or rufous, the lower parts varied with 
white, or even banded with orange. JMJerulaxis has long, stiff 
loral plumes, Rhinocrypta lanceolata a crest, and several forms 
elongated rump-feathers. In Acropternis the back and abdomen 
are ocellated with white. The sexes are nearly similar. 
These peculiar birds are commonly shy and retiring, hopping 
actively about with erect tails, or running lke mice, but rarely fly- 
ing, except between the boughs and the ground. They are decidedly 
difficult of observation, though they follow up the pedestrian under 
cover, betraying their position by their scolding cries. Many 
species, such as Hylactes tarnii, the “ Guid-guid,” Pteroptochus 
rubecula, the “ Cheu-can,” and 7riptorhinus paradoxus, the “ Cheu- 
