CANVAS-BACK DUCK. 



109 



drab ; back dusky white crossed with fine waving lines ; belly of 

 the same dull white, pencilled like the back; wings, feet, and 

 bill, as in the male; tail coverts dusky, vent white waved with 

 brown. 



The windpipe of the male has a large flattish concave laby- 

 rinth, the ridge of which is covered with a thin transparent mem- 

 brane ; where the trachea enters this it is very narrow, but imme- 

 diately above swells to three times that diameter. The intestines 

 are wide, and measure five feet in length. 



VOL. VIII. 



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