312 
ON THE CLASSIFICATION OF BIRDS. 
hangs, therefore, over other divisions of this family, 
we feel fully persuaded that Cymindis is the tenuirostral 
genus of the Falconida, a further confirmation of 
which, by the way, will he found in its closed nostrils, 
opening only by an oblique slit — a universal character 
among all the humming birds, no less than in the order 
of Waders. The affinity of Cymindis to Potyhorus 
may be traced in the thickened bill, long wings, and 
short hind toe ; and we shall now proceed to establish 
its connection with Nauclerus, a form justly separated 
by Mr. Vigors* from the other kites, and represented by 
that beautiful and graceful bird, the swallow or fork- 
tailed kite of America {fig. 105.) In this type many 
of the characters of Cymindis are retained ; but they are 
combined with others very dissimilar. The bill {fig. 1 06.) 
is equally hooked ; but 
it is smaller, and there 
is a small half-angulated 
festoon in the middle of 
the upper mandible : the 
feet, and the proportion- 
ate length of the toes and 
of their claws, are all 
the same ; but the legs 
are even still shorter, so that the hinder toe, when 
measured from its base, is exactly the length of the 
tarsus: its exclusive characters, therefore, are almost 
* Zoological Journal, ii. p. 386 28. 
