INTRODUCTION. Vii 
Vireonide, Tanagride, Icteride, Tyrannide, Cotingide, Formicariide, Pteroptochide, 
Caprimulgide, Trogonidee, and Cracidee (1 each). 
Out of the total number of 1413 species enumerated, 636 are endemic. Of these 
latter, 271 are peculiar to (a) Mexico, Honduras, or Guatemala, 3 to (0) Nicaragua, 
and 162 to (c) Costa Rica or Panama, the remainder (189) being more widely 
distributed within the region or common to two of these divisions. 
The Trochilidz include 118 species, with 84 endemic; the Fringillidee 104, with 52 
endemic; the Tanagride 86, with 46 endemic; the Formicariide 52, with 28 endemic; 
the Dendrocolaptide 47, with 26 endemic ; the Troglodytide 46, with 30 endemic; the 
Turdide 41, with 24 endemic; the Psittacide 34, with 24 endemic; the Phasianide 
32, with 25 endemic; the Peristeride 30, with 19 endemic; the Cotingide 26, with 
12 endemic; the Trogonide 16, with 11 endemic; the Cracide 14, with 12 endemic; 
the Tinamide 11, with 8 endemic; and the Rhamphastide 10, with 7 endemic. 
It will thus be seen that these fifteen families are all rich in peculiar forms, and that 
the families themselves are almost all tropical. On the other hand, a large number of 
species belonging to the more widely distributed genera find their winter home in 
Mexico and Central America, or even further south, returning to breed in the 
Nearctic Region, some Humming-birds (such as Trochilus colubris and Selasphorus 
rufus) and others wandering far north at this season. Jt would be very interesting 
to show the lines of migration of many of the species, but we have not sufficient data 
for this purpose. Some of them, no doubt, travel southward from the United States to 
the mainland of South America by way of the Caribbean or the West Indian Islands, 
perhaps just touching the eastern part of our region en route. Others probably find 
their way down the central tablelands, and a few western species, again, pass down the 
lowlands of the Pacific coast. 
The Tres Marias, Coiba, and Pearl Islands in the Pacific, and the islands of 
Cozumel, Mugeres, Holbox, Ruatan, and Old Providence in the Atlantic, possess 
various slightly modified forms; and the Revillagigedo Islands are the home of 
numerous interesting sea-birds not found on the mainland. 
To summarize the results, the Avifauna of Central America may be described ‘as 
essentially Neotropical, with certain peculiar forms (such as Oreophasis derbianus, 
