1916] Chandler: Structure of Feathers 339 



more basal portion of barb, for the most part not exceeding one- 

 third the length of the base, broad basally, tapering rapidly to a 

 slender but short filament. 



Outer vane. — Distal harhules (pi. 24, fig. 42c) even shorter than 

 on inner vane, total length under 0.5 mm., the base constituting 

 about one-half of this. Base slightly curved longitudinally, with 

 lobate ventral teeth not as broad as in inner vane. Pennulum with 

 booklets about as in the inner vane. Ventral cilia more nearly sub- 

 equal to each other for the whole length of the pennulum, strongly 

 curved, and well separated from each other. Dorsal cilia in the 

 form of short prongs. 



Proximal harhules on proximal portions of the barbs closely 

 resembling those of the inner vane, but pennulum even shorter. 

 On the outer portion of the barbs, the proximals (pi. 24, fig. 4:2d, 

 42e) with ventral teeth proliferated and transformed into a series 

 of stout, strongly hooked ventral cilia, in some cases almost exactly 

 like booklets in form, more numerous on more distal barbules, but 

 only 3 to 5 basal ones strongly hooked. 



(2) Other Feathers 

 Body feathers, where there are no special color modifications, 

 merely simplifications of remex type, distal barbules resembling 

 outer vane type, proximals the inner vane type. Vanes not firmly 

 interlocking and usually a large portion of feather downy. After- 

 shaft with well-formed shaft, its vanes distinct and separate, barbs 

 attached in linear series as in contour feathers, and not tuftlike 

 as is more usual. Vanules of the interlocking or pennaceous por- 

 tion always open, i. e., barbules in a vertical plane and therefore 

 with spaces between them. Distal harhules with long, slender bases, 

 with more or less reduced ventral teeth. Pennulum with 3 to 5 

 short, weakened booklets followed by a series of the same type of 

 short, curved, infiexible and subequal ventral cilia as in the 

 remiges, these becoming short and more or less rudimentary in 

 looser feathers. Proximal harhules (pi. 24, fig. 42/) with elongated, 

 tapering bases, with moderate, rather slender, ventral teeth. Pen- 

 nulum short, as in remiges, almost invariably considerably less 

 than half length of base ; no cilia. 



h) Other Types 



The minute structure of the remiges is remarkably constant 

 throughout the group, and it is possible to distinguish a gallinaceous 

 bird from all others very easily by the structure of its remiges. The 

 description of the feathers of Gallus domesticus will hold, with very 

 slight modification, for all the Phasianidae. 



In the Tetraonidae the pennulum of the more terminal proximal 

 barbules of the outer vane has a longer series of ventral cilia, which 

 are relatively somewhat shorter, and of more uniform size. In some 

 members of the family the ventral ridge of the barbs is extremely 

 broad, as in Anserine birds. See plate 24, figures 43a, h, and c. 



