MITEEPHANES. — EMPIDONAX. 67 



Originally described from a Cordova specimen, with which others from Jalapa, 

 Orizaba, Cofre de Perote, &c. agree. They are all rather darker than examples from 

 the valley of Mexico, Oaxaca, and the Sierra Madre of North-western Mexico, the 

 latter having been described by Mr. Brewster as M. p. temirostris. 



The diflFerence of colour is extremely slight, but follows the usual rule where the 

 birds of Eastern Mexico, with its greater rainfall, are rather darker than those from 

 the drier plateau and the western sierras. The difference in the size of the bill is 

 hardly appreciable in the series before us. In the series obtained by Mrs. Smith in the 

 months of July and August in the Sierra Madre del Sur are light and dark coloured 

 birds as well as young in their first plumage. 



In Guatemala M. phceocercus is common in the oak-forests lying at an elevation of 

 4500 feet and upwards, and is one of the most characteristic species of these woods. 

 We never met with its nest or eggs. 



2. Mitrephanes aurantiiventris. 



Mitrephorus aurantiiventris, Lawr. Ann. Lye. N. Y. viii. p. 174 \ ix. p. 114 ^ ; Salv. Ibis, 1869,. 



p. 315 ' J P. Z. S. 1870, p. 198 ' ; v. Frantz. J. f. Orn. 1869, p. 308'. 

 Mitrephanes aurantiiventris, Scl. Cat. Birds Brit. Mus. xiv. p. 219 °. 

 Mitrephorus phaocercus, Lawr. Ann. Lye. N. Y. ix. p. 114''. 



Prsecedenti similis, sed supra magis olivaceus, abdomine medio aurantiaco distinguendus. (Descr. exempl. ex 

 Irazu, Costa Eioa. Mus. nosfcr.) 



Hah. Costa Eica, Tabacales ^ La Palma 2, Candelaria [v. Frantzius ^ ^), Tucurriqui {Arc6)y 

 Irazu {Bogers), Dota 2, Barranca {Carmiol) ; Panama, Volcan de Chiriqui, Chitra, 

 Calovevoria *, Calobre {ArcH). 



The specimens of this species differ considerably from each other in the colouring of 

 the top of the head, some being much darker than others ; but this variation seems to 

 be due to individual, seasonal, or perhaps sexual characters. 



M. aurantiiventris is closely allied to the bird of the Mexican and Guatemalan high- 

 lands, M. phceocercus, but appears to frequent places lying at a lower level, descending 

 in some cases as low as 2000 feet above the sea. It is a common bird both in Costa 

 Rica and the State of Panama, but its nest and eggs still remain unknown. 



EMPIDONAX. 



Empidonaaa, Cabanis, J. f. Orn. 1855, p. 480 (type E. pusillus (Sw.)) ; Scl. Cat. Birds Brit. Mus. 

 xiv. p. 221. 



Empidonax is one of the most complex genera of the Tyrannidse as regards the 

 differential characters of some of its species, comparable in this respect to the 

 Old- World genus Phylloscopus. Several distinguished American ornithologists have 

 paid great attention to Empidonax, and descriptions, "keys," and all such aids to 



9* 



