Vol. XXIII 

 1906 



] Clark, Pterylosis of Swifts and Hummingbirds. 79 



indicating its position. The secondaries are usually 6, but not 

 uncommonly 7, in number, and the wing seems to be generally 

 aquincubital, though in several cases examined it was clearly 

 quincubital. In one instance one wing had 6 secondaries and was 

 clearly aquincubital as in Paiagona, while the other wing had 7 

 secondaries and was as certainly quincubital. Apparently this 

 point in wing structure is no longer of significance in the humming- 

 birds. The skin on the hand is often very dark, and this color 

 extends more or less markedly onto the forearm. 



This account of the trochiline pterylosis is based on the careful 

 examination of 31 hummingbirds, representing 17 species and 15 

 genera, and on Thompson's (: 01) very valuable study of Patagona 

 gigas, Nitzsch's ('40) figure and description of Chrysolampis mo- 

 schitus, Shufeldt's ('88) account of Selasphorus platycercus, and 

 Lucas's ('92) figure and brief description of Florisuga mellivora. 

 So far as I know, no other hummingbirds have ever been examined 

 pterylographically. The various genera will now be considered 

 in detail. 



Campylopterus. 



Reference is made to this genus only because Lucas ('92) states 

 that the skin of the hand is "colored black" as in the swifts and 

 some other hummers. 



Florisuga. 



The single specimen examined showed no peculiarities, except 

 that there were apparently only 9 primaries, doubtless accidental 

 or an abnormal condition. The skin on the hand is black. 



Specimen examined. 



The figure and description of this genus given by Lucas ('92) 

 are fairly good, though 1 find no tendency in the sternal tracts to 



