1834.] ZOOLOGY. 237 
to believe that the land was once joined, and thus allowed ani- 
mals so delicate and helpless as the tucutuco and Reithrodon to 
pass over. The correspondence of the cliffs is far from proving 
any junction ; because such cliffs generally are formed by the in- 
tersection of sloping deposits, which, before the elevation of the 
land, had been accumulated near the then existing shores. It is, 
however, a remarkable coincidence, that in the two large islands 
cut off by the Beagle Channel from the rest of Tierra del Fuego, 
one has cliffs composed of matter that may be called stratified 
alluvium, which front similar ones on the opposite side of the 
channel,—while the other is exclusively bordered by old erystal- 
line rocks: in the former, called Navarin Island, both foxes and 
guanacos occur; but in the latter, Hoste Island, although simi- 
lar in every respect, and only separated by a channel a little more 
than half a mile wide, I have the word of Jemmy Button for‘ 
saying, that neither of these animals are found. 
The gloomy woods are inhabited by few birds: occasionally 
the plaintive note of a white-tufted tyrant-flycatcher (Myiobius 
albiceps) may be heard, concealed near the summit of the most 
lofty trees; and more rarely the loud strange cry of a black 
woodpecker, with a fine scarlet crest on its head. A little, dusky- 
coloured wren (Scytalopus Magellanicus) hops in a skulking 
manner among the entangled mass of the fallen and decaying 
trunks. But the creeper (Oxyurus tupinieri) is the commonest 
bird in the country. Throughout the beech forests, high up and 
low down, in the most gloomy, wet, and impenetrable ravines, it 
may be met with. This little bird no doubt appears more nu- 
merous than it really is, from its habit of following with seeming 
curiosity any person who enters these silent woods: continually 
uttering a harsh twitter, it flutters from tree to tree, within a 
few feet of the intruder's face. It is far from wishing for the 
modest concealment of the true creeper (Certhia familiaris) ; nor 
does it, like that bird, run up the trunks of trees, but industri- 
ously, after the manner of a willow-wren, hops about, and 
searches for insects on every twig and branch. In the more 
open parts, three or four species of finches, a thrush, a starling (or 
Icterus), two Opetiorhynchi, and several hawks and owls occur. 
The absence of any species whatever in the whole class ‘of 
Reptiles, is a marked feature in the zoology of this country, as 
