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. 
BAAN o oys 6. cross as a,c, 238, or 55 a as 
Costa Rica .......... 317, or 74 ap a 
Guatemala and Mexico 210, or 49 ss ee 
North America ...... 60, or 14 ip Be 
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... 2. 15, or 33 per cent. of the ascertained fauna. 
Veragua...... 29, or 7 e i 
Costa Rica.... 35, or 7 ry He 
79 
Veragua and Costa Rica have in common.... 49 species 
Veragua and Panama ss zi jizz ess 
Veragua, Panama, and Costa Rica ,, PR} Mae 
Costa Rica and Panama eS REP ie a >: 
96 
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 por- 
tion 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 32 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 
