<< DISTAL PROXIMAL - ——————_—________» 
LESSER COVERTS 
OUTER WEB 






MIDDLE _COVERTS 
INNER WEB 
PRIMARY COVERTS EEE LER COVERTS 
WS 
ib TERTIAL COVERTS 
: An PANS \ 

SCAPULARS 
~ a 
TERTIALS 
L- 
PRIMARIES SPECULUM SECONDARIES 
Plate 1. TYPICAL DABBLING DUCK WING 

