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 crystal- 

 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 mor*> 

 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 vhe zoology of this country, as 



