THE EIDER DUCK. 



361 



the duodenum, h i j, ^ inch, 

 diminishing to 5 twelfths; the 

 rectum, Fig. 2, a b, 7 twelfths 

 in width; the cceca, c c, 3|- 

 inches long, 4 inches distant 

 from the extremity; their great- 

 est width 4^ twelfths, for an 

 inch at the base only 1 twelfth; 

 the cloaca very slightly dilated, 

 its breadth being only 8 twelfths. 

 The trachea is 9% 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 1^ inches from the tympa- 

 num they give off the cleido- 

 tracheal muscles, and at the 

 tympanum itself the sterno- 

 tracheal. 



Fi<r. 2. 



Vol. VI. 



50 



