340 University of California Publications in Zoology Vou. 18 
In the Meleagridae the distal barbules of the remiges have the 
ventral teeth enormously developed as broad, thin filmlike sheets, 
while the hooklets are very long and slender, almost as much so as 
in Olor. See plate 24, figures 44a, 440. 
In the Megapodidae and Cracidae, as exemplified by the genera 
Megapodius and Penelope, the structure of the feathers is very 
similar to each other, both varying a little from the usual type. In 
the remiges of Megapodius and Penelope the distal barbules (pl. 24, 
fig. 45a, 46a) are characterized by a rather elongate base, somewhat 
sinuate in ventral profile, with relatively small ventral teeth. The 
hooklets and ventral cilia are of typical gallinaceous form, but the 
dorsal cilia differ in the shghtly stouter, more thornlike form of the 
basal two. The proximal barbules which possess ventral hooklike 
barbicels (pl. 24, fig. 45b) are restricted to a smaller portion of the 
tip of the barbs. 
The body feathers, where there are no special color modifications, 
undergo a similar simplification and assume a very similar form, 
in nearly all gallinaceous birds. The aftershaft, when developed, is 
of the form described for Gallus domesticus, with well-developed 
shaft and distinct separate vanes; the vanes of the main feather 
plate are always of the open type; the barbules are nearly always 
at least recognizably similar; the distals with curved, hooklike 
ventral cilia, the proximals with relatively extremely short pennula. 
c) Down 
The down barbules of gallinaceous birds differ considerably on 
different portions of the barbs, and to some extent on different 
barbs (see Part I, p. 270), but reach their highest and most typical 
development on the basal portion of the distal vanule of the well- 
developed down barbs of the main feather plate. 
These typical barbules (pl. 36, fig. 108) are readily distin- 
euishable from those of any other group of birds. They are densely 
set, sometimes as many as 50 per millimeter on each side near the 
base of the barbs, though always considerably less at the middle 
and tip. They are usually extremely long, reaching a length of 
over 5 mm. in various species of pheasants and turkeys, though as 
a rule they are more nearly 3 mm. in length. The base of these 
barbules is only slightly differentiated. The pennulum on its more 
proximal portion has poorly developed swollen nodes (pl. 36, fig. 
108b), which, however, soon increase in size and develop a typical 
