342 SURF DUCK. 



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 f- 

 inch in diameter. The intestine, 5 feet 7 inches in length, has an average 

 diameter of 6 twelfths. The rectum is 7^ inches long, S twelfths in diame- 

 ter. Of the cceca one is 3 inches 4 twelfths long, cylindrical, obtuse, 2^- 

 twelfths in diameter, the other 4 J inches long. 



The aperture of the glottis is S 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 1^ 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, ^ 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. 



