72 
THE EIDER DUCK. 
the duodenum, h i j, i inch, 
diminishing to 5 twelfths ; the 
rectum, Fig. 2, a b, 7 twelfths 
in width; the coeca, c c , 3§ 
inches long, 4 inches distant 
from the extremity : their great- 
est width W twelfths, for an 
inch at the base only 1 twelfth ; 
the cloaca very slightly dilated, 
its breadth being only8 twelfths. 
The trachea is inches long, 
nearly of the uniform width of 
5 twelfths, moderately flattened ; 
the rings 130, well ossified, end- 
ing in a transversely oblong 
dilatation, projecting more to- 
ward the left side, 1 inch in 
breadth, \ inch in length. Bron- 
chial half rings 32, the bronchi 
very wide, rings very narrow 
and cartilaginous. The contrac- 
tor muscles are very large, and 
expanded over the whole ante- 
rior surface. At the distance 
of 1J inches from the tympa- 
num they give off the cleido- 
tracheal muscles, and at the 
tympanum itself the sterno- 
tracheal. 
Fig. 2. 
