479 PASSERIFORMES CHAP. 
In the males of some forms the remiges differ from those of the 
females; thus the shafts of the primaries are thickened and 
pointed in Chiroxiphia, similar but imcurved in Helicura and 
Chiromachaeris, with much attenuated barbs in the latter; in 
Ptilochloris the seventh primary is modified and bends outwards. 
In Machaeropterus the wing-bones are flattened; the secondaries 
have thick stems bending inwards towards the tip, and shew reduced 
vanes, save the eighth and ninth, while the sixth and seventh have 
the shaft terminally developed into a horny excrescence. The tail 
is usually short and square, but is long in Chloropipo and Metopia, 
rounded in the latter and Masius, graduated in Metopothrix and 
Heterocercus. The outer of the twelve feathers are much elongated 
in Cirropipra, being acuminate in C. heterocerca, curved and filiform 
in C. filicauda; the two median rectrices are lengthened in Helicura ; 
while in three species of Chiroxiphia they are also long, or even 
linear in C. linearis. Frontal crests occur in MMetopia, Masius, 
and Metopothriz ; vertical crests in Pipra serena, P. suavissima, 
and four species of Chiroxiphia ; Ceratopipra has a peculiar ex- 
tended nuchal tuft, Chiromachaeris an elongated beard. 
As examples of coloration we may take the following :-—C2loro- 
pipo flavicapilla has a yellow head, neck, and under parts, a green 
back, and brownish wings ; Yenopipo 
atronitens is uniform black; Cerato- 
pipra cornuta, black with scarlet head, 
neck, and thighs; Cirropipra. fili- 
cauda similarly coloured, with yellow 
forehead and lower surface.  Pipra 
leucocilla is black with a white 
crown; P. velutina has a blue cap, 
P. suavissima an erect white vertical 
crest, lilac rump, and orange mid- 
abdomen.  Machaeropterus  requlus 
exhibits green upper parts, a scarlet 
crown, slaty wing- and _ tail - quills, 
and white, green, and rufous under 
surface. Chiroxiphia pareola is black, 
with blue mantle and crimson crest 5 
Chiromachaeris aurantiaca is also black, with orange nuchal band, 
cheeks and breast, green rump, and yellow abdomen. The 
females are green, with yellowish or whitish tints below. Ptilo- 
Fic. 102.—Manakin. Pipra 
mentalis, x4. 
