THRYOTHORUS. 121 
The characters of these two divisions will be found detailed in 
the introductory remarks, and under their respective heads. T'rogio- 
dytes, with its two sections, is very closely related to Thryothorus, 
as restricted, so much so that it is very difficult to draw the line. 
The supposed differences referred to by many authors resulted from 
the comparison of T’roglodytes with Thryophilus, rather than with 
true Thryothorus. 
In the following synopsis I present an artificial key to the species 
of Thryothorus, Pheugopedius, and Thryophilus, found in North 
and Middle America, with their nearest South American allies, and 
based entirely on color and markings. 7. plewrostictus I know only 
by description, and may not have worked it in properly. A more 
natural arrangement, based upon the peculiarities of structure, fol- 
lows the first. 
Synopsis of Species. 
A. Head above and back of much the same color. 
a, Crissum barred transversely; rest of under parts 
spotted or banded conspicuously with black (ex- 
cept in felix). 
1. Outside of wings banded; head like the 
back. 
a. Throat white; rest of under parts black, 
finely banded with white . : . fasciato-ventris. 
&. Under parts pure white; sides from 
neck to crissum banded with black .  pleurostictus. 
2. Outside of wings plain; head more rufous 
than the back. Sides of head and neck 
white, conspicuously streaked with black; 
wings longer than tail, except in felix. 
a. Beneath white, spotted with black from 
chin to belly. Flanks rusty : maculipectus. 
8, Chin and upper throat black, hathen 
with white; rest of under parts plain 
rufous 5 é : - rutilus. 
y- Beneath aha waesaua on sides 
brown. Upper tail covert barred. Tail 
longer than the wings . . : - feliz. 
b. Crissum barred transversely; rest of under parts 
plain. 
1. Upper tail coverts and exposed surface of 
wings barred. 
a. Tail feathers reddish-brown, barred 
with black. Greater wing coverts spot- 
ted with whitish. 
1. Beneath rusty white . ; -  ludovicianus. 
2. Beneath rusty brown . : - berlandieri. 
