MITREPHANES,—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 MZ. p. tenuirostris. 
The difference 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 UZ. pheocercus 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. Lyc. N. Y. viii. p. 174’, ix. p. 114°; Salv. Ibis, 1869, 
p- 315°; 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 pheocercus, Lawr, Aun. Lyc. N. Y. ix. p. 114’. 
Preecedenti similis, sed supra magis olivaceus, abdomine medio aurantiaco distinguendus. (Descr. exempl. ex 
Irazu, Costa Rica. Mus. nostr.) 
Hab. Costa Rica, Tabacales 1, La Palma 2, Candelaria (v. Frantzius 25), Tucurriqui (Arcé), 
Irazu (Rogers), Dota 2, Barranca (Carmiol); Panama, Volcan de Chiriqui, Chitra, 
Calovevora +, Calobre (Arcé). 
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. pheocercus, but appears to frequent places lying at a lower level, descending 
in some cases as low as 2000 feet above the sea. It isa common bird both in Costa 
Rica and the State of Panama, but its nest and eggs still remain unknown. 
EMPIDONAX. 
Empidonax, Cabanis, J. f£. Orn. 1855, p. 480 (type E. pusilius (Sw.)); Scl. Cat. Birds Brit. Mus. 
Xiv. p. 221. 
Empidonaxz is one of the most complex genera of the Tyrannide 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 Hmpidonasz, and descriptions, “ keys,” and all such aids to 
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