EXPLANATION OF PLATES 



Except as otherwise noted, all figures of barbules are from a 

 typical portion of a typical barb of the feathers it represents, and 

 drawn in lateral view, the distals with their bases to the left, the 

 proximals to the right, and in all cases dorsal side uppermost on the 

 plate. 



PLATE 13 



Rheiformes and Stkuthionifobmes 



All figures except 2d, X 85 



Fig. 1. Rhea americana. 



a. Barbule from basal portion of barb from terminal part of remex. 

 &. Barbule from basal third of barb from middle portion of rump 



feather, 

 c. Barbule from middle portion of barb from middle part of remex. 



Fig. 2. Struthio camelus. 



a. Barbule from remex. 



&. Barbule from back feather. 



c. Barbule from black wing covert. 



d. Elongated barb from back feather of chick (neossoptile). X 10- 



e. Barbule from back feather of chick (neossoptile). 



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