MTI0DI0CTE8.— BASILEUTEEUS. 169 



forehead and chin being almost orange, by the greater brightness of the steel-blue 

 gloss of the cap, and other minor characters. 



Dr. Coues ^^ remarking on the distribution of these varieties, says that M. pileolatus 

 is not restricted to the Pacific coast region, and that his Arizona specimens are precisely 

 like Pennsylvanian ones. He therefore places both varieties under the same name ; and 

 we follow him in so doing ; for though we recognize both races in our Central- American 

 series of specimens, we are, like him, unable to trace their distribution definitely, and 

 consequently leave the species undivided. If any thing, the so-called western race is 

 most prevalent in Costa Rica and Panama — that is, at the extreme southern limit of the 

 range of the species. This is contrary to what we usually find ; for when two species or 

 races inhabit the northern continent, it is the eastern and not the western form that has 

 the most extended range in the winter season. 



Myiodioctes jausillus is a well-known Mexican and Guatemalan species in the winter 

 months, being distributed all over the country, from near the sea-level to an altitude 

 of 5000 or 6000 feet. At Duenas we used frequently to meet with it in second- 

 growth woods and in willow trees on the banks of the Eio Guacalate. In Costa Rica 

 Dr. V. Frantzius met with it between August and March, and as high as 7000 feet in 

 the Poas volcano. Some of Carmiol's specimens were obtained as late as April ^^, 



In North America M. pusillus is chiefly known as a bird of passage, its breeding- 

 quarters extending northwards of Massachusetts, except in the higher mountains of the 

 west ^^. But little, however, has been recorded of its breeding-habits, and this long ago 

 by Audubon and Nuttall, the former naturalist having described a nest he found in 

 Labrador, and the latter one from Oregon. That this species breeds in the higher 

 mountains of Nevada, Colorado, and Arizona there can be no doubt, as the testimony 

 of Messrs. Eidgway and Henshaw, and also of Dr. Coues, indicates that it is found 

 during the summer months in these regions ; but as yet no nests have been discovered 

 there ^^. The eggs are described as white, finely sprinkled round the larger end with 

 brownish red and lilac ^^. 



BASILEUTEEUS. 



Basileuterus, Oabanis in Schomb. Reisen Guiana, iii. p. 666 (1848). (Type "Sylvia vermivora, 

 Vieillot," 2ia.ct., = Basileuterus auricapillus (Sw.) apud Berlepsch, Ibis, 1881, p. 240.) 



In having a narrow nearly even tail of about the same length as the wings, and a 

 broad depressed bill with well-developed rictal bristles, this genus resembles Myio- 

 dioctes ; but the wings are more rounded, and the first primary shorter ; the culmen, 

 too, is more curved. Moreover all the members of Myiodioctes are of migratory 

 habits, and spend the summer in North America, and the winter in Central America; 

 whereas the species of Basileuterus are, so far as we know, of non-migratory habits, all 

 belonging to the Neotropical region. 



Basileuterus is the largest genus of the Mniotiltidse, containing more species than 

 BIOL. CBNTE.-AMEK., Aves, Vol. I., October 1881. 22 



