Tyrant Shrikes of America. 279 



I am ignorant of the locality of this species, which is de- 

 scribed from a specimen in my collection. 

 Total length 6f, bill l T \y, wings 3$, tail 2}, tarsi •&. 



Sp. 15. Tyrannu3 ambulans. Sp. Nov. 

 Walking Tyrant. 



T. olivaceo-fuscus, infrk flavus ; jugulo rectriciumque apicibus pallidioribus; 

 crista aurantiac& ; remigibus primoribus acuminatis; tarsis elongatis, va- 

 lidis. 



Olive-brown, beneath yellow ; throat and tips of the tail paler; crest orange ; 

 primary quills pointed; tarsi lengthened, robust. 



The power of locomotion, in the more characteristic exam- 

 ples of this family, is principally confined to the wing, but 

 in the bird before us, this faculty is equally divided between the 

 wings and the legs. Habitually frequenting the ground, upon 

 which it walks and occasionally runs like a lark, it nevertheless 

 is an air-feeding bird ; for, during these excursions, it is perpe- 

 tually making short, and nearly perpendicular, flights after such 

 insects as have just taken wing. Notwithstanding every watch- 

 fulness on my part, I never could detect this bird using its feet 

 in any other situation than on the ground. 



I met with a few individuals of T. ambulans, during my stay at 

 Pernambuco, frequenting the sandy pastures on the outskirts of 

 the town ; but I never again saw the bird during my travels in 

 the other provinces. 



Size rather larger than the Cayenne Fly-catcher ; bill black, rather 

 long 1 , and resembling in form that of T. sulphuratus. Plumage above 

 drab-coloured brown, beneath yellow, verging towards white on the 

 chin and throat. Wings and tail deep brown ; the latter moderate and 

 even, having the side feathers tipt with yellowish-white: the front and 

 sides of the head are greyish-brown, and the crest is orange-red. The 

 two first primary quills are not emargiuate, but are rather shorter than 

 usual, and gradually pointed. The legs, as before observed, are long and 

 robust. 



Total length 7i, bill 1, wings 3|, tail 3, tarsi 1, middle claw nearly one 

 inch. 



Sp. 16. Tyranntjs nengeta. 

 Black and white- winged Tyrant. 



T. griseus, albus infra ; alis caudSque nigris ; remigum primorum basi, secun- 

 dorum apicibus, rectricibusque, albis; tarsis elongatis. 



