75 Clark, Pterytosis of Swifts and Hummingbirds. [jan 



10 primaries; of the latter, the ninth is the longest, and even the 

 eighth is longer than the tenth. There are 10 secondaries, the 

 wing is quincubital, and the alula consists of 2 feathers. 



Specimens examined. 



Aeronautes. 



This genus is notable for the very small nuchal apterium hut 

 in other respects is very similar to Choetura. The legs are feath- 

 ered in front to the base of the toes. The skin on the hand is very 

 dark. There are 10 rectrices, and 10 primaries of which the ninth 

 is longest.. The wing is quincubital and has 9 secondaries and 3 

 feathers in the alula. 



Specimens examined. 



No. 



Name. 



Collection. 



Condition. 



leronautes melanoleucus(B&ird) I". S. Nat. Museum. 



Alcoholic; good 



Micropus. 



The humeral tracts in this genus are somewhat peculiar, for 

 in melba they seem to have a small horizontal branch on the inner 

 side extending in towards the dorsal, while in wquatorialis and 

 streubeli, they pass very nearly over the head of the humerus and 

 thus are nearer the dorsal tract than in Choetura. In melba, the 

 nuchal apterium is short and wide, but in the others is long and 

 narrow. The legs are feathered to the toes in front, in equatorial is- 

 and streubeli, but only about half way down the tarsus in melba. 

 The skin on the hand is very dark but not on the forearm. Of 



