282 Mr. Swainson on the 



Section IV. 



Alse longse, remigum pogoniis internis emarginatis. 

 Cauda longissima, forficata. 



The Muscicapa Tyrannus of Linnaeus (the Savana of Buffon) 

 may be taken as the type of a division strongly characterized by 

 the tail being unusually long and very deeply forked ; this struc- 

 ture, aided by a corresponding power in the wings, enables these 

 birds to fly with a rapidity even greater than that exerted by 

 those of the second division ; both groups approach each other in 

 general conformation, but the different form of their tails, and a 

 variation in their economy, seem to warrant a separation. The 

 habits of the Tyranni in general are solitary; for, although 

 several of the same species may be seen within a limited dis- 

 tance, they never act in concert; but the Tyrannus furcatus is in 

 some degree gregarious ; it shews a fondness for the society of its 

 own species, and frequently assembles in the air in bands of near 

 two hundred. Whether this is for the purpose of pursuing 

 insects, or preparatory to migration, M. Vieillot (who quotes the 

 authority of Azara) has not distinctly stated ; but the fact itself 

 is curious, and moreover points out a considerable resemblance to 

 the gregarious habits of the African Drongos ; the typical groups 

 of which are no less remarkable for the great length of their tails. 

 There are but few birds, yet known, referrible to this section. 

 The variety of T. Savana, said to be found in Canada, may pro- 

 bably be distinct. The Muscicapa forficata of Latham is known 

 to me only by the figure in Buffon, but from that it seems to 

 possess the typical characters in great perfection ; a fourth spe- 

 cies, which I believe is here described for the first time, will com- 

 plete the list. 



Sp. 17. Tyrannus Savana. Vieil. 

 Fork-tailed Tyrant. 



T. cinereus, albus infra ; vertice auribusque nigris; alis fuscis; cauda longis- 

 sima, valde furcata, nigra. 



Cinereous, beneath white; crown and ears black; wings brown; tail very 

 long, deeply forked, and black. 



Muscicapa Tyrannus. Lin. 1. 325. Ind. Orn. 2. 484. 

 Le Tyran a queue fourchue. Brisson, Ois. 2. pi. 39. f. 3. 

 Fork-tailed Fly-catcher. Gen. Syn. 3. p. 355. 

 Tyrannus Savana. Vieil. Ois. Am. 1. pi. 43. 



