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Show 270 ISLAND LIFE. [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 ~nterest 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 thjrty-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 :- 1. Mimus trifasciatus 2. , me1anotus 3. , parvulus 4. Dendrooca aureola ... 5. Progne concolor 6. Certhidea olivacea 7 , fusca ... TURDIDJE • .. . } This and the two allied species are . . . related to a Peruvian bird Mimus . .. longicaudus. MNIOTILTID.lE. { Closely allied to the wide-ranging D. ·· · restiva. HmuNDINIDJE. { Allied to P. purpurea of North and "· · · · South America. CCEUEBID.lE. } A peculiar genus allied to the Andean. genns Conirostrum. OIIAP. XIII.] THE GALAPAGOS ISLANDS. 271 FRINOILLIDJE. , strenua. ... ... , dubia... .. . 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. Geospiza mngnirostris , . ·1 " fortis.·· · · · ... ~A distinct genus, but allied to the , r1ebulosa ... ... ... , South American genus Guiraca. , fuliginosa .. . , parvula .. . , dentirostris ::: J , assimilis . . . . .. Cactornis scandens . . . . . . . .. } , abingdoni .. . . .. A genus allied to the last. , pallid a .. . .. . .. . Camarhynchus psittaculus ... ~ , cra~siro stris . . . A very peculiar grnus allied to N eo- " vanegatus . . . rhynchus of the west coast of , prosthemelus... Peru, , habeli ... ... J !CTERrDJE. 25. Dolichonyx oryzivorus . . . Ranges from Canada to Paraguay. TYUANNIDJE. 26. Py~ocephalus nat;ms.. .. . . . . . . Allied to P. rubineus of Ecuador. 27. My1archus magmrostns ... ... Allied to West Indian species. 28. Zenaida galapagensis CoLUMBID.lE. ... .. . {A peculiar species of a S. American genus. FA LCONTD.lE. 29 Buteo galapagensis. .. . .. . .. A buzzard of peculiar coloration. STRIGIDJE. 30. Asio galapagensis .. . 31. Strix punctatissima .. . { Hardly distinct from the wide-spread · · · A. brachyotus. . . . Allied to i:3.jlammea but quite distinct. We have here every gradation of difference from perfect identity with the continental species to aenera so distinct that it is difficult to determine with what form~ they are most nearly allied; and it is interesting to note that this diversity bears a distinct relation to the probabilities of, and facilities for, migration to the islands. The excessively abundant rice-bird, which breeds in Canada and swarms over the whole United States mjgrating to the \Vest Indies and South America visitina the' ' b |