12 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
i. Tail more graduated; larger (total length about 170 mm.); adult 
male wholly black below.............. Othello (extralimital).2 
wi. Tail less graduated; smaller (total length less than 150 mm.); 
adult males with sides and flanks white or grayish. 
Hypolophus (p. 32). 
gg. Bill relatively much smaller and weaker (exposed culmen shorter 
than middle toe with claw), less strongly uncinate; crest less con- 
spicuously developed. 
h. Tail at least four-fifths as long as wing; larger and stronger forms. 
i, Bill larger and stouter, the exposed culmen much more than 
half as long as tarsus. 
j. Feathers of forehead much developed, the crest occupying 
entire pileum; male with a white throat-patch and black 
jugular area, the remaining under parts fulvous. 
Biatas (extralimital).6 
jj. Feathers of forehead short, semi-decomposed, the crest con- 
fined to crown and occiput; adult males with under parts 
barred with black and white, or else uniform gray or slate 
color (rarely streaked with white). 
&. Bill more swollen, with tip less compressed, its width at frontal 
antiz equal to its depth at same point, and equal to much 
more than half the distance from nostril to tip of maxilla; 
adult males conspicuously barred with black and white, 
or gray streaked with white, beneath, females rufous above. 
Thamnophilus (p. 34). 
kk. Bill less swollen laterally, more compressed terminally, its 
width at frontal antize less than its depth at same point 
and equal to not more than half the distance from nostril 
to tip of maxilla; adult males plain gray, slate color, or 
black below, females gray, olive, or brown above. 
Erionotus (p. 47). 
wi. Bill smaller and more slender, the exposed culmen not more than 
half as long as tarsus, its depth at frontal antie equal to not 
more than half the distance from nostril to tip of maxilla. 
Rhopochares (extralimital).+ 
hh. Tail less than three-fourths as long as wing; smaller and weaker 
forms. wavvemworseearieeecesee se esse ee Dysithamnus (p. 52). 
cc. Nostril more or less narrow and longitudinal, more or less distinctly opercu- 
late, or if broadly oval or roundish the remainder of nasal fosse occupied 
by membraneous integument. 
d. Plumage softer, more lax, and semi-decomposed, especially on rump. 
(Formicivore.) 
e. Planta tarsi distinctly scutellate, at least on inner side or posterior margin. 
@ Othello Reichenbach, Av. Syst. Nat., 1850, pl. 71. Type, Lanius luctuosus Lich- 
tenstein. (Amazon Valley; monotypic?) [I have not been able to examine 7. 
leuconotus Spix, T. xthiops Sclater, T. tschudit Pelzeln, nor 7. melanochrous Sclater 
and Salvin, which Dr. Sclater places in the same ‘“‘section” with T. luctuosus.] 
b Biastes (not of Panzer, 1806) Reichenbach, Handb., 1853, 175. Type, Anabates 
nigropectus Lafresnaye.—Biatas Cabanis and Heine, Mus. Hein., ii, Aug., 1859, 19 
(new name for Biastes Reichenbach, preoccupied), (Southeastern Brazil; monotypic.) 
¢ Rhopochares Cabanis and Heine, Mus. Hein., ii, Aug., 1859, 17. Type, Thamno- 
philus torquatus Swainson. (Paraguay, Uruguay, Argentina, southeastern Brazil, and 
Bolivia; three species). 
