58 PROCEEDINGS OF THE ACADEMY OP 



broad opposite the nostrils, and a little shorter than the tarsus, 

 which latter somewhat exceeds the middle toe and claw in length; 

 and with the occipital and coronal feathers somewhat lanceolate 

 and lengthened into a slight crest. 



Coloration is a good arbitrary clue to the genus. The upper 

 parts are more or less olive, sometimes clear and bright, sometimes 

 grayish or brownish ; the throat is more or less ash}', variable in 

 shade ; the belly is more or less yellow, from a rich shade to a 

 mere trace; and the wing and tail feathers are marked with rufous, 

 sometimes intense, and occuqrying the whole of certain feathers, 

 sometimes reduced to a mere trace; but even in those species, in 

 which it is at a minimum, it may be detected in some specimens. 

 If one will lay the following birds side by side, one will see this 

 distinctive brand of coloration running through them all, though 

 at first sight such a form as antillarum does not particularly re- 

 semble validus. The Tyranni afford a parallel series between ex- 

 tremes, from the most olivaceous yellow-bellied species, like verti- 

 calis, to the dark ashy white-bellied carolinensis. Still, in a cer- 

 tain per cent, of specimens of several Myiarchi the rufous is 

 ordinarily imperceptible. 



Judged by the foregoing standard, " Blacicus" tristis is a pure 

 Myiarchus ; in fact, it is the insular representative of nigriceps, as 

 stolidus is of lawrencei. " Blacicus" pallidas, however, falls unde r 

 " Contopus," owing to the smallness of the feet. " Tyrannus" 

 antillarum, Bryant, referred by Gray to typical Tyrannus, is 

 certainly a true Myiarchus, being simply an insular variety of M. 

 stolidus. But this error of Gray's is a slight matter, compared with 

 his assignment of stolidus itself to an entirely different genus of an- 

 other sub-family; this bird being pure Myiarchus, only specifically 

 distinguishable from M. lawrencei as its insular representative. I 

 know nothing of the "Onychopterus tuberculifer Lafr." which 

 Gray interpolates betwixt the larger and smaller species of typical 

 Jli/iarchus; but I suspect it does not belong just here. Likewise 

 I have not seen four other species ascribed to the genus, viz. : 

 tricolor, cantans and gracilirostris, Pelzeln, and fasciatus, Landb. ; 

 so I cannot sa}' whether or not they fall in the group as here de- 

 fined; but there is little, if any doubt, that they belong here. 

 Excepting these, I have before me, I believe, types or typical spe- 

 cimens of all the described species of Mxjiarchus ; and these I 

 purpose to elaborate in this paper. And that I may not be mis- 



[July 2, 



