SURF DUCK. 
53 
twelfths broad, its lateral muscles very large, the right 10 twelfths thick, the 
left 9 twelfths. In the stomach were various small bivalve shells and much 
gravel. The cuticular lining longitudinally rugous ; the grinding plates I 
inch in diameter. The intestine, 5 feet 7 inches in length, has an average 
diameter of 6 twelfths. The rectum is 74 inches long, 8 twelfths in diame- 
ter. Of the cceca one is 3 inches 4 twelfths long, cylindrical, obtuse, 24 
twelfths in diameter, the other 44 inches long. 
The aperture of the glottis is 8 twelfths long, with numerous minute 
papillae behind. The trachea presents the same structure as that of the 
Velvet Duck. Its upper rings, to the number of 9, are very narrow, and 
continuous with a large bony expansion 7 twelfths long, and 8 twelfths 
broad. Beyond this part its diameter is 5 twelfths, gradually diminishes 
to 3 twelfths about the middle, then enlarges to 5 twelfths. In this part the 
number of rings is 78. Then comes a roundish or transversely elliptical 
enlargement, 1 inch 2 twelfths in breadth, 9 twelfths in length, convex 
before, slightly concave behind, and composed of about 12 united rings. 
The trachea then contracts to 4 twelfths and presently enlarges to form the 
inferior larynx, which is large, ossified, but symmetrical. In this space 
there are 6 distinct rings, and 10 united. The entire length of the trachea 
is 74 inches, its rings are all osseous and strong. The contractor muscles 
are very strong, pass along the sides of the lower dilatation, on which are 
given off the cleido-tracheals, then continue to the commencement of the 
inferior larynx, where the sterno-tracheals come off. The bronchial half- 
rings 25, unossified. 
The cavity of the nose is very large, being 2 inches long, 4 inch in 
diameter at the lower part, continued narrow in front over the dilatation 
causing the external protuberance of the base of the bill. The olfactory 
nerves are of moderate size ; the maxillary branches of the fifth pair very 
large. 
