270 
ISLAND LTFE. 
[part II. 
to sea on a tree uprooted by a flood such as often occurs in 
tropical climates and especially during earthquakes. To some 
such accident we may perhaps attribute the presence of 
these creatures in the Galapagos, and that it is a very rare one 
is indicated by the fact that only two species have as yet 
succeeded in obtaining a footing there. 
Birds. — We now come to the birds, whose presence here may 
not seem so remarkable, but which yet present features of in- 
terest not exceeded by any other group. Fifty-seven species 
of birds have now been obtained on these islands, and of these 
thirty-eight are peculiar to them. But all the species found 
elsewhere, except one, belong to the aquatic tribes or the waders 
which are pre-eminently wanderers, yet even of these eight are 
peculiar. The true land-birds are thirty-one in number, and all 
but one are entirely confined to the Galapagos ; while more than 
half present such peculiarities that they are classed as distinct 
genera. All are allied to birds inhabiting tropical America, 
some very closely ; while one — the common American rice-bird, 
which ranges over the whole northern and part of the southern 
continents — is the only land-bird identical with those of the 
mainland. The following is a list of these land-birds taken 
from Mr. Salvin’s memoir in the Transactions of the Zoological 
Society for the year 1876 : — 
Turdid,®. 
1. Mimus trifasciatus ... 1 This and the two allied species are 
2. ,, melanotus ... > related to a Peruvian bird Mimus 
3. „ parvulus J longicaudus. 
Mniotiltid^e. 
, _ , , f Closely allied to tbe wide-ranging D. 
4. Dendrceea aureola ( mt wa. 
HlRUNDIXIDiE. 
„ ^ , f Allied to P. purpurea of North and 
5. Progne concolor ( South America. 
C(EREBIDiE. 
6. Certhidea olivacea \ A peculiar genus allied to the Andean, 
-7 ■ „ fusca / genus Conirostrum. 
