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Show 178 MR. o. SALVIN ON THE BIRDS OF VERAGUA. [Mar. 24, and, further, it now appears that the connexion with the Isthmus of Panama is hardly greater than with the more northern portions of Central America. These results may be exhibited as follows in a tabular form : - Total number of species found in Veragua, 432. Number of Veraguan species also found in South America 179, or 41 per cent of the whole. Panama 238, or 55 Costa Rica 317, or 74 Guatemala and Mexico 210, or 49 North America 60, or 14 J» »» >> I find that the number of birds which are not found outside the limits of Panama, Veragua, and Costa Rica, or that part of Central America included between the Isthmus of Darien and the Lake of Nicaragua, is altogether about 175 species; or, if we take the whole bird-fauna of this district, at say 720, 25 per cent, are peculiar. These 175 species are distributed as follows :- Number peculiar to Panama 15, or 3| percent, of the ascertained fauna. Veragua 29, or 7 ,, „ Costa Rica. ... 35, or 7 ,, ,, 79 Veragua and Costa Rica have in common. Veragua and Panama ,, Veragua, Panama, and Costa Rica „ Costa Rica and Panama „ 49 14 26 7 96 79 species 3 J >> >> Add peculiar species 79 175 Thus, viewing this section of the Isthmus as a whole, we find that, without making any deductions whatever, no less than 25 per cent. of its bird-population is unrepresented specifically in any other portion of the adjoining regions. When, however, we take a portion of this country and compare it with the rest of the whole district, we find that the greatest amount of peculiarity does not exceed 7 per cent.; and the least amount reaches as low as 3| per cent. The characteristic elements of the Central-American fauna consist not so much in the amount of generic peculiarity, which is very small, but in the fact that a very considerable portion of South- American forms are here represented, not as specifically identical, but, in a large number of instances, as definably distinct in degrees of varying value. The element of the Central-American bird-fauna to be traced to the northern continent, on the other hand, maintains a very different relationship to the bird-fauna of that continent. With the exception of a few species isolated in the mountains of the higher |