TROCHILID. 249 
Order MACROCHIRES. 
Suborder TROCHILI. 
Fam, TROCHILIDA. 
This purely Neogean Family of birds contains, according to the most recently 
prepared catalogue, about 470 species, which are divided into 127 genera. Of these 
no less than 118 species, belonging to 50 genera, occur within the limits of Central 
America and Mexico. By far the larger number of these inhabit the more tropical 
portion of the country, the number of species becoming less as the northern frontier is 
approached, and, on the other hand, they are more numerous both in species and 
genera in the mountainous parts of Costa Rica and the State of Panama. Thus, in 
Northern Mexico we can only record 14 species, while in Costa Rica and Panama we 
know of the existence of no less than 65, Southern Mexico possessing 48, and Guate- 
mala 38. Though the Trochilide are thus fully represented in our country, there 
are still a very considerable number of genera, mostly belonging to the Andes, not 
found within our limits. They include some of the most remarkable forms of the 
Family: thus we do not find any representative of Diphlogena, Helianthea, or Bourci- 
eria, nor Cyanolesbia, Sappho, or Lesbia, Heliangelus or Urosticte, and many other 
brilliant forms. Nor do any of the characteristic genera of the higher Andes occur, 
such as Oreotrochilus, Oreonympha, Rhamphomicron, Oxypogon, Agleactes, or Erio- 
cnemis. Nevertheless our region has 20 genera belonging to it, none of which are 
found in the southern continent: these are Jache, Pheoptila, Microchera, Callipharus, 
Eupherusa, Elvira, Panterpe, Arinia, Basilinna, Sphenoproctus, Pheochroa, Eugenes, 
Caligena, Oreopyra, Delattria, Lamprolema, Abeillia, Tilmatura, Calothorax, and 
Atthis. This is a much larger proportion of genera peculiar to our region than is 
found in any other group of birds, and is due in a great measure to the treatment the 
Trochilide have received as regards the subdivision of genera, which has been carried 
further than in any other Family of birds. At the same time it must be noted that 
this very remarkable group, so specialized as a whole, is very highly differentiated 
as regards its species, and the genera, numerous as they are, do no more than link 
together the most obviously allied forms. If any considerable reduction of their 
number were attempted, the result would hardly prove satisfactory, as the uniformity 
of many genera would scarcely fail to suffer thereby. In fact many more genera than 
the number here accepted have been proposed, so that the present system is a com- 
promise between the extreme views held on this point. 
BIOL. CENTR.-AMER., Aves, Vol. II., May 1892. 32 
