80 



Clark, Pterylosis of Swifts and Hummingbirds. 



["Auk 

 |_Jan. 



connect with each other near the furculum, either in Florisuga or 

 any other hummer, as indicated in Lucas's figure. Moreover the 

 head and wing are too closely feathered, and the humeral tracts 

 are not well enough defined. Incidentally, I wish to dissent 

 strongly from Lucas's statements as to the reasons for the exist- 

 ence of the various apteria. 



Patagona. 



The pterylosis of this genus, so admirably figured and described 

 by Thompson (:01), deserves special mention because of the pres- 

 ence of 7 secondaries in the aquincubital wing, and of a "lateral 

 tract" just outside of the sternal tract. This small tract occurs 

 in no other genus of Trochili, so far as I know, but a similar tract 

 occurs in Todus, according to Nitzsch's figure. It would be in- 

 teresting to know if the tract has any special significance in Pata- 

 gona or is composed of feathers in any way peculiar, or different 

 from those which make up the sternals. 



Argyrtria. 



There is nothing exceptional or worthy of note in this genus, 

 except that the formula for the length of the rectrices is 3-2-4-1-5. 



Specimen examined. 



Eucephala. 



The general pterylosis is like that of Trochilus alexandri. There 

 are 6 secondaries in the right wing, with 7 major coverts, and the 

 wing is clearly aquincubital, but in the left wing there are 7 well 

 developed secondaries, of nearly equal size, and only 7 major 

 coverts, the wing being perfectly quincubital. The tail is slightly 



