462 Mr. R. Ridgway on the Genus Empidonax. 
typical species only in coloration, and not essentially in this 
respect. 
Both Mitrephanes and Empidochanes are nearly related to 
Empidonax , hut seem to be sufficiently distinct to pass for 
genera, as genera go among Passerine birds. Compared 
with Empidonax , their more obvious characters are as fol¬ 
lows :— 
Mitrephanes. Rictal bristles much more lengthened, 
pileus much more conspicuously crested, bill narrower at 
tip and more depressed; wings and tail proportionately 
longer, and feet weaker; tail more deeply emarginate than 
in any species of Empidonax. Includes M. phceocercus, M. 
aurantiiventris , Lawr., and “Empidonax” atriceps, Salv. 
Empidochanes. Bill much less depressed, as well as rela¬ 
tively longer, its depth at base being decidedly greater than 
one half the width; tail decidedly rounded instead of even 
or emarginated. Includes Muscicapa fuscata, Max., Musci- 
capa oliva, Bodd. (?), M. fringillaris, Licht., and perhaps E. 
poecilurus, Scl., and E. poecilocercus (neither of which have I 
seen), but not Empidonax brunneus 9 Ridgw., which I have 
been able to compare with the types of Muscicapa fuscata , 
Max., in the American Museum, New York. 
Key to the Species of Empidonax. 
a 1 . Width of hill at nostrils decidedly greater than half 
the length of the exposed culmen. 
b l . Lower parts deep huff, deepening into ochraceous 
on breast and sides. 
c L . Upper parts deep hair-brown. 
d 1 . Lower parts soft pinkish buff, inclining to 
isabelle colour on breast, paler on throat and 
belly, nearly white on under tail-coverts. 
Wing 2 - 70 inches, tail 2‘45; culmen, mea¬ 
sured in each case from extreme base, 0‘52 ; 
tarsus 0-60; width of bill at base, measured 
at anterior extremity of feathering of forehead, 
0-21.— Sab. Eastern Mexico (north into 
Southern Texas P) . E. fulvifrons. 
d 2 . Lower parts bright ochraceous buff, inclining 
to deep ochraceous on breast and pale buffy 
