It is unusual for oceanic islands to possess snakes, and it is therefore somewhat of an anomaly that two species are found in the Galapagos. Both are closely allied to South American forms, and one is hardly different from a Chilian snake, so that they indicate a more recent origin than in the case of the lizards. Snakes it is known can survive a long time at sea, since a living boa-constrictor once reached the island of St. Vincent from the coast of South America, a distance of two hundred miles by the shortest route. Snakes often frequent trees, and might thus be conveyed long distances if carried out 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 interest not exceeded by any other group. About seventy species of birds have now been obtained on these islands, and of these forty-one 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 forty-two in number, and all but one are entirely confined to the Galapagos; while three-fourths of them present such peculiarities that they are classed in 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, to which are added nine species collected in 1888 and {281} described by Mr. Ridgway in the _Proceedings of the U.S. National Museum_ (XII. p. 101) and some additional species obtained in 1889. TURDIDAE. 1. Nesomimus trifasciatus } This and the two allied species 2. ,, melanotus } are related to a Peruvian bird 3. ,, parvulus } _Mimus longicaudus_. 4. ,, macdonaldi (Ridg.) 5. ,, personatus (Ridg.) MNIOTILTIDAE. 6. Dendroeca aureola { Closely allied to the wide-ranging { _D. aestiva_. HIRUNDINIDAE. 7. Progne concolor { Allied to _P. purpurea_ of North { and South America. COEREBIDAE. 8. Certhidea olivacea } A peculiar genus allied to the 9. ,, fusca } Andean genus Conirostrum. 10. ,, cinerascens } FRINGILLIDAE.