360 University of California Publications in Zoology  {\Vou.18 
29, fig. 67a). Proximal barbules differ from those of remiges in 
base being relatively slender, with inconspicuous ventral teeth, the 
pennulum being.extremely slender and filamentous, nearly as long 
as base. 
Breast feathers, as exemplified by Melopelia asiatica, with both 
kinds of barbules characterized by elongation of bases, which are 
relatively more slender than in back feathers, and very great 
elongation of the slender threadliike pennula. Distal barbules (pl. 
29, fig. 66b) have slender base, all barbicels reduced, and pennu- 
lum two or three times length of base on more proximal part of 
vanule, shorter than base on distal part of vanule. Proximal bar- 
bules (pl. 29, fig. 66c) with similarly elongated base and extremely 
long pennulum, several times length of base on proximal part of 
vanule, about equal to it on distal part. 
b) Other Types 
In the majority of the Columbidae the remiges have a structure 
very closely similar to that described above for Columba livia. A 
very unusual and probably recent departure from the ordinary 
type is to be found in the forked primaries of Drepanoptila, in 
which the entire feather plate is double on the terminal portion. 
Goura coronata differs widely from the other Columbidae in 
the character of the proximal dorsal cilia of the distal barbules of 
the inner vane (pl. 29, fig. 70a), which are large and specialized 
as stout, lobelike projections as in herons and vultures. In other 
respects the distal barbules, and in all respects the proximal bar- 
bules, resemble those of typical Columbidae. The coverts, scapulars, 
and back feathers undergo very little modification in the different 
genera except for production of color. (See plate 29, figure 66a, 
covert from Melopelia; figure 68a, covert from Macropygia; figure 
69a, covert from Osmotreron). The breast feathers also differ but 
slightly in different groups. Even in Goura coronata, which has 
feathers differing most widely from the type of any species in the 
family, the breast feathers are remarkably similar to those of other 
columbids (pl. 29, figs. 70c, 70d). The barbules on the loose-vaned 
crown feathers of Goura (pl. 29, fig. 70e) have lost their pennula 
and the bases are cigar-shaped. 
In the Pteroclidae, exemplified by Pteroclis arenarius, the distal 
and proximal barbules of the inner vane (pl. 29, fig. 7la, 71lc) are 
distinetly of typical columbid type, but those of the outer vane 
differ in having very short pennular cells with long, slender ventral 
cilia and very short, knoblike dorsal cilia. The scapular feathers 
have the peculiarities of the pennulum of the distal barbules still 
