82 TYEANNID^. 



Contopus borealis, Scl. P. Z. S. 1858, p. 301", 1859, pp. 44", 366", 384"; Scl. & Salv. Ibis, 

 1859, p. 122 ". 



Supra griseo-olivaceus ; pileo obsouriore ; alis et cauda fusco-nigricantibus, illaram tectiicibas et secundariis 

 pallide fasco obscure limbatis ; remige primo in pogonio extemo albo marginato : subtus sordide olivaceo- 

 grisescens ; gula pallidiore ; abdomine medio fulvescente, lateribus plaga magna alba celata omatis : rostri 

 maxilla fusca, mandibula flava j pedibus obscure corylinis. Long, tota 8*0, alae 4*3, caudae rect. med. 3*4, 

 rect. lat. 3-7, tarsi 0-7, rostri a rictu 0*9. (Descr. exempl. ex Jalapa, Mexico. Mus. nostr.) 



Av. juv. obscurior, tectricibus et secundariis alarum fulyo conspicue limbatis, 



Eai. NoETH America, Southern Arizona ^ *. — Mexico {Bulloch ^), Sierra Madre of 

 Sonora and Chihuahua, Eio Verde, Yecera, Tutuaca {W. Lloyd), Ciudad in 

 Durango {Forrer), Mazatlan and Tepic (Grayson ^^), Plains of Colima (Xantus i°), 

 Omilteme, Chilpancingo, Amula and Eincon in Guerrero (Mrs. IT. H. Smith), 

 Chimalpa, Ixtapalapa, Tetelco (Ferrari-Perez), Chietla and Actopam (Ferrari- 

 Perez ^^), State of Vera Cruz (Sumichrast ^), Jalapa ^ (de Oca ^^, Edge, M. Trujillo), 

 Cofre de Perote (M. Trujillo), Parada i^, Cinco Senores ^^ (Boucard), Sta. Gertrudis 

 (GaleoUi% Gineta Mts. (Sumichrast ^i) ; British Honduras, Southern Pine Ridge 

 near Cayo (Blancaneaux) ; Guatemala (Skinner ^^), Volcan de Fuego ^, Volcan de 

 Agusi (0. S. & F. D. Q.^). 



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 pertinax 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 specimea from Colorado. 



