350 University of California Publications in Zoology [Vol.13 



barbule evenly tapering for wliole length, dorsal edge with complete 

 and contiiuious series of flexules and dorsal cilia, ventral edge with 

 rather short, slender, more or less appressed ventral cilia. More 

 distal barbs have this structure for three-fourths of their length. 



T)) Other Types 



The structure of the feathers in all species of Grus is probably 

 very similar, and there is a similar freeing of the barbs of the 

 terminal part of the scapular feathers in nearly all, if not all, of 

 the species. 



In the Ballidae the structure of the feathers differs in some 

 important details, approaching more closely to that of the Limicolae. 

 In the remiges of Rallus ohsoletus, the proximal and distal barbules 

 are more numerous, being about 26 and 37 per millimeter respect- 

 ively. The distal barbules (pi. 26, fig. 52a) have a relatively long 

 base, about 0.25 mm. long by 0.035 mm. wide, becoming very nar- 

 row proximal to the small, fingerlike ventral teeth, a condition 

 exactly similar to that in the Limicolae. The pennulum is rather 

 narrow except in the booklet region, the booklets 5 in number, and 

 slender, and the cilia, both ventral and dorsal, very similar to those 

 in the Limicolae (compare plate 26, figure 52a, with plate 28, figure 

 57a.) The proximal barbules (pi. 26, fig. 52&) have relatively 

 small bases, about 0.5 mm. long by 0.04 mm. wide, with ventral 

 teeth moderately developed, while the pennula are shorter than the 

 bases, and flattened. On the outer vane the distal barbules show 

 no especially interesting characters, but the proximal barbules 

 (pi. 26, fig. 52c) on the distal half of the barb have pennula longer 

 than the bases furnished with a highly developed series of ventral 

 cilia, of which the more proximal ones are hooked. In this char- 

 acter the rails differ from both the Limicolae and Gruidae. In 

 Cresiciis the ventral cilia of the proximal barbules of the outer vane 

 are less hooked, while in Gallinula, although the pennulum is very 

 long and is sharply bent with respect to the base, as in Rallus, the 

 ventral cilia, except two or three basal ones, are not developed. 



In the body feathers of Rallus obsoletus (also of Cresicus, Gal- 

 linula, and other species of Rallus) the structure of the feathers 

 is strikingly peculiar, even at the very base of the barbs. As shown 

 by plate 26, figures 52d, e, and /, the distal barbules, from base 

 to tip of the barb, change from a form with three weak booklets 

 and rudimentary flexules and cilia, to a form with no differen- 



