1916] Chandler: Structure of Feathers 345 



short, stout hooklets and short, curved, inflexible ventral cilia, but 

 only the proximal ones developed. 



(4) Proximal barbule with base moderate and ventral teeth 

 well developed but not conspicuous, those of distal part of barbs of 

 outer vane with well-developed series of ventral cilia, the proximal 

 one hooked. 



(5) Barbules of back and breast feathers mere simplifications of 

 remex type. 



In the following characters they differ from typical Galli : (1) 

 poor development of barbicels on terminal part of pennulum and 

 stout, thornlike form of first two dorsal cilia of distal barbules ; 



(2) rather long, filamentous pennulum of proximal barbules; and 



(3) moderately long down barbules with slightly enlarged un- 

 pigmented nodes, the internodes with black pigment. 



8. Order CRYPTURIFORMES 

 Plate 25 

 This order, which includes the aberrant South American tin- 

 amous, has in some ways the most specialized feather structure of 

 any existing birds. They form a compact group of some forty 

 species, all in the family Tinamidae. They differ from all other 

 birds in having plumules present between the contour feathers, 

 while absent in the apteria. The aftershaft is rudimentary or 

 absent in some genera but large and well developed, with distinct 

 vanes, in other genera (e. g., Rhynchotes). Although strictly ground 

 birds which can fly very poorly and have a remarkable lack of con- 

 trol of the flight powers they do possess, the small wings have remiges 

 which are very well developed. 



a) Tinamus soUtarius 



(1) Remex 



Calamus short and of smaller caliber than shaft. Shaft slightly 

 wider than deep, with small median groove. Vanes extremely firm 

 and elastic, the harhs adhering to each other with remarkable ten- 

 acity. Rami not deep, the ventral ridge rather narrow ; about 25 

 per centimeter on each side basally, 16 to 18 for greater part of 

 feather. 



Inner Vane. — Distal harhules (pi. 25, fig. 49a) relatively very 

 small, base very short and broad, about 0.35 mm. long by 0.04 

 wide, the ventral teeth broad, lobate, and filmlike. Pennulum, in 

 side view, of peculiar shape, narrow in booklet region, then becom- 

 ing very broad (about 0.15 mm.) and thence tapering evenly to tip. 



