DUSKY DUCK. 23 
rous minute papille behind. ‘The cesophagus 12 inches long, of a uni- 
form diameter of ;4,, until near the lower part of the neck, where it 
enlarges to 78, again contracts as it enters the thorax, ending in the 
proventriculus, which is 1} long, with numerous oblong glandules, 
about a twelfth in length. Gizzard obliquely elliptical, 2} inches 
across, 1,8, in length, its lateral muscles extremely large, the left }¢ in 
thickness, the right ,%; their tendons large and strong; the lower 
muscle moderately thick; the cuticular lining firm and rugous, the 
grinding surfaces nearly smooth. The intestine, which is 5 feet 74 
inches long, is slender and nearly uniform in diameter, measuring ;5 
across in the duodenal portion, 3, in the rest of its extent; the rectum 
33 inches long, dilated into a globular cloaca 1 inch in length, and of 
nearly the same diameter. The ceca are 6} long, }4 in diameter for 
2 inches of their length, enlarged to ,% in the rest of their extent, and 
terminating in an obtuse extremity. 
The trachea, moderately extended, is 10 inches long. Its lateral or 
contractor muscles are strong, and it is furnished with a pair of cleido 
tracheals, and a pair of sterno-tracheals. The number of rings is 136, 
besides 12 united rings forming a large inferior larynx, which has a 
transversely oblong bony expansion, forming on the left side a bulging 
and rounded sac. There are 28 bronchial half rings on the right side, 
26 on the left. 
