190 Proceedings of the Biological Society of Washington. 



Venezuela and French Guiana. Specimens from the latter country are 

 topotypical, and average a little smaller than usual, while those from Vene- 

 zuela are a httle larger, but the difference is not excessive. Birds from the 

 Dutch West Indies have been separated by Dr. Hartert on the ground of 

 smaller size and generally paler color above. As shown by the above table 

 of measurements, examples from Curasao are actually larger than those 

 from the type-locality, while we can not verify the alleged color-differences 

 after a careful study of our series. Two birds from Tobago are not dis- 

 tinguishable in any way either, so far as we can see. Comparing now these 

 northern birds, considered collectively, with a good series from Brazil 

 (Matto Grosso), Bohvia, and Argentina, we fail to distinguish the latter 

 by any constant characters. The form chlorepiscius was based on just 

 three specimens from Matto Grosso, but the characters assigned are of 

 absolutely no diagnostic value in view of the large amount of variation 

 obtaining in this species. At first glance it would seem as if southern birds 

 had rather more cinnamon rufous in the tail than northern, but further 

 study shows that this feature is inconstant, and varies in all parts of the 

 range. There are specimens from Colombia, Venezuela, Guiana, and 

 Brazil which have very little cinnamon rufous in the tail, thus approaching 

 the race bahice. In the series from Matto Grosso there is a perfect gradation 

 from specimens having a broad inner rufous margin to the outer rectrices 

 to those showing none at all, and which could be referred to bahioe just as 

 well as not. Allen has already remarked on this variation, but it must be 

 added that some of the specimens on which he based his remarks turn out 

 to be pelzelni. Taking everything into consideration, therefore, we can not 

 discover any good reasons for recognizing any geographical races of this 

 species except bahioe and pallescens, since the slightly larger size of more 

 southern birds is such a small matter. The present form has a rather 

 peculiar range, not passing beyond the Andes anywhere except in the 

 Caribbean coast district of Colombia, but apparently extending southward 

 along the east base of the Andes into Peru, Bohvia, and Argentina, leaving 

 the greater part of Brazil to be occupied by the race bahice, with which it 

 intergrades in Matto Grosso. Light and dark birds occur throughout this 

 extensive range, and have no geographical significance. 



Myiarchus tyrannulus has had an eventful nomenclatural history. It 

 was described by Brisson in 1760 and independently figured by D' Aubenton 

 a few years later, the figure serving as the basis for Mtiller's name, applied 

 in 1776, and for Boddaert's in 1783. Latham and Gmelin considered it as 

 a "variety" of what is now known as Myiarchus Jerox. Vieillot described 

 it under still another name. D'Orbigny and Lafresnaye confused it with 

 the North American M. crinitus, and Coues made it a variety of that form. 

 Cassin was the first to point out the priority of Miiller's name in 1864, but 

 it was misapplied until revived by Sclater in 1888, the species having in the 

 meantime been again christened by Sclater in 1868 as erythrocercus. We 

 have already discussed the status of the supposed subspecies chlorejyiscius, 

 brevipennis, and tobagensis. 



Specimens examined. — Colombia: Bonda, 5; Cautilito, 1: Mamatoco, 5; 

 La Tigrera, 4; Fundacion, 6; Rio Hacha, 3; Turbaco, 4; Palmar, 4; "Santa 



