1916] Chandler: Structure of Feathers 345 
short, stout hooklets and short, curved, inflexible ventral cilia, but 
only the proximal ones developed. 
(4) Proximal barbule with base moderate and ventral teeth 
well developed but not conspicuous, those of distal part of barbs of 
outer vane with well-developed series of ventral cilia, the proximal 
one hooked. 
(5) Barbules of back and breast feathers mere simplifications of 
remex type. 
In the following characters they differ from typical Galli: (1) 
poor development of barbicels on terminal part of pennulum and 
stout, thornlike form of first two dorsal cilia of distal barbules; 
(2) rather long, filamentous pennulum of proximal barbules; 
(3) moderately long down barbules with shghtly enlarged un- 
pigmented nodes, the internodes with black pigment. 
and 
8. Order CRYPTURIFORMES 
Plate 25 
This order, which includes the aberrant South American tin- 
amous, has in some ways the most specialized feather structure of 
any existing birds. They form a compact group of some forty 
species, all in the family Tinamidae. They differ from all other 
birds in having plumules present between the contour feathers, 
while absent in the apteria. The aftershaft is rudimentary or 
absent in some genera but large and well developed, with distinct 
vanes, in other genera (e. g., Rhynchotes). Although strictly ground 
birds which can fly very poorly and have a remarkable lack of con- 
trol of the flight powers they do possess, the small wings have remiges 
which are very well developed. 
a) Tinamus solitarius 
(1) Remezx 
Calamus short and of smaller caliber than shaft. Shaft slightly 
wider than deep, with small median groove. Vanes extremely firm 
and elastic, the barbs adhering to each other with remarkable ten- 
acity. Rami not deep, the ventral ridge rather narrow; about 25 
per centimeter on each side basally, 16 to 18 for greater part of 
feather. 
Inner Vane.—Distal barbules (pl. 25, fig. 49a) relatively very 
small, base very short and broad, about 0.35 mm. long by 0.04 
wide, the ventral teeth broad, lobate, and filmlike. Pennulum, in 
side view, of peculiar shape, narrow in hooklet region, then becom- 
ing very broad (about 0.15 mm.) and thence tapering evenly to tip. 
