340 University of California Publications in Zoology I Vol. 13 



In the Meleagridae the distal barbules of the remiges have the 

 ventral teeth enormously developed as broad, thin filralike sheets, 

 while the booklets are very long and slender, almost as much so as 

 in Olor. See plate 24, figures 44a, 446. 



In the Megapodidae and Craeidae, 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 (pi. 24, 

 fig. 45«, 46a) are characterized by a rather elongate base, somewhat 

 sinuate in ventral profile, with relatively small ventral teeth. The 

 booklets and ventral cilia are of typical gallinaceous form, but the 

 dorsal cilia differ in the slightly stouter, more thornlike form of the 

 basal two. The proximal barbules which possess ventral hooklike 

 barbicels (pi. 24, fig. 456 ) 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 domesiicus, 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 (pi. 36, fig. 108) are readily distin- 

 guishable 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 (pi. 36, fig. 

 108&), which, however, soon increase in size and develop a typical 



