82 TYRANNIDZ. 
Contopus borealis, Scl. P. Z. S, 1858, p. 301*°, 1859, pp. 44°, 366, 384"°; Scl. & Salv. Ibis, 
1859, p. 122, 
Supra griseo-olivaceus ; pileo obscuriore; alis et cauda fusco-nigricantibus, illarum tectricibus et secundariis 
pallide fusco obscure limbatis ; remige primo in pogonio externo albo marginato: subtus sordide olivaceo- 
grisescens; gula pallidiore; abdomine medio fulvescente, lateribus plaga magna alba celata ornatis: rostri 
maxilla fusca, mandibula flava; pedibus obscure corylinis. Long. tota 8:0, ale 4:3, caude rect. med. 3°4, 
rect. lat. 3°7, tarsi 0°7, rostri a rictu 0-9. (Descr. exempl. ex Jalapa, Mexico. Mus. nostr.) 
Av. ju. obscurior, tectricibus et secundariis alarum fulvo conspicue limbatis. 
Hab. Nort America, Southern Arizona’ *.—Mexico (Bullock'), Sierra Madre of 
- Sonora and Chihuahua, Rio Verde, Yecera, Tutuaca (W. Lloyd), Ciudad in 
Durango (Forrer), Mazatlan and Tepic (Grayson 19), Plains of Colima (Xantus 1°), 
Omilteme, Chilpancingo, Amula and Rincon in Guerrero (Irs. H. H. Smith), 
Chimalpa, Ixtapalapa, Tetelco (Ferrari-Perez), Chietla and Actopam (Ferrari- 
Perez '8), State of Vera Cruz (Swmichrast’), Jalapa? (de Ocal", Hoge, M. Trujillo), 
Cofre de Perote (IZ. Trujillo), Parada *, Cinco Sefiores 1® (Boucard), Sta. Gertrudis 
(Galeotti ®), Gineta Mts. (Sumichrast 1); British Honpuras, Southern Pine Ridge 
near Cayo (Blancaneaux); GuaTEMALA (Skinner 1°), Volcan de Fuego 3, Volcan de 
Agua (0. 8. & F. D. G.4). 
The birds from the Sierra Madre of North-Western Mexico, including those from 
Southern Arizona belonging to the same mountain-system, are of a greyer cast of 
plumage than the typical form of Contopus pertinar from Jalapa, those of the valley 
of Mexico agreeing with the northern rather than with the eastern type. The bird 
of Guatemala appears to be of a browner colour on the upper plumage and not so grey 
as that of the Western Sierra Madre; but it differs little, except in being rather small, 
from the Jalapa bird. Moreover the differences appear to be to some extent due to 
season and age, the young individuals being darker and browner than the old ones. 
This is especially to be noticed in Mrs. Smith’s specimens from the Sierra Madre del 
Sur in Guerrero; the older birds resemble those of the valley of Mexico, the younger 
ones those of the Eastern Sierras. Perhaps the most distinct of these forms is that 
found in Guatemala, the bird of the State of Vera Cruz being intermediate, but we 
see no sufficient grounds for giving any of them separate names. 
It is probable that only in the northern and higher portion of its range this species is 
migratory. It certainly breeds in Arizona, the Sierras of Durango, Cofre de Perote, &c., 
and also in Guatemala, as specimens before us were shot in September, at which time 
birds were still in the Sierras of Arizona. | 
There can be little doubt that Swainson’s name Tyrannula musica is applicable to 
this bird and has many years’ priority over Contopus pertinax of Cabanis and Heine. 
Unfortunately the former title has been entirely overlooked since it was published, so 
that the latter has come into general use. We believe C. musicus to be strictly 
applicable to the bird of the tablelands and thence northwards to Arizona. If separ- 
* Capt. P. M. Thorne (Auk, 1887, p. 264) records a single specimen from Colorado. 
