AMERICAN SWAN. 



233 



Fig. 1 



outer lamellae only 22. Bill along the ridge 4i inches, from the angle of the 

 eye to the tip 4|§; lower mandible along the edge 3^; depth of bill at the 

 angle of the mouth 1 T 9 2, its breadth at the nostrils 1 T 4 2 -, near the end l/j. 

 The roof of the mouth is deeply concave, with a medial prominent line, on 

 which is a series of hard tubercles. The width of the mouth is 1 inch 5 

 twelfths. The eyes are very small, their diameter being 5 twelfths, the 

 aperture of the ear 4 twelfths. The internal cells are of vast size; the right 

 thoracic being 4 inches long, the right abdominal 6 inches, the right hepatic 

 5^, the left hepatic 4, the left abdominal 3i, the left thoracic 3. The heart 

 is proportionally of large size, being 3 inches 2 twelfths in length, 2 inches 

 10 twelfths in breadth. The oesophagus, Fig. I, a b c, is 2 feet 2 inches 

 long, much narrower than the intestine, its average diameter being only 4 

 twelfths, but at the lower part of the neck it dilates to 8 twelfths; on 

 entering the thorax, it passes obliquely to the left side, and the proven- 

 triculus, b c, has a diameter of 1 inch 2 twelfths. The inner coat of the 

 oesophagus is thrown into strong longitudinal rugae, and the muscular coat 

 consists of two layers, the outer composed of longitudinal, the inner of 

 transverse fibres. The stomach, d efg, is obliquely situated on the left side, 

 and is an extremly developed muscular gizzard, of an elliptical form, its 

 length being 2 inches 6 

 twelfths, its breadth 3 

 inches 10 twelfths. The 

 right lateral muscle g, is 1 

 inch 9 twelfths thick, the 

 left e, 1 inch 4 twelfths. In 

 the stomach is a large mass 

 of very fine quartz sand, 

 and a great number of ger- 

 minating seeds of an ellip- 

 tical form, some about 5 

 twelfths long, and of a 

 brownish-yellow colour, to- 

 gether with shoots of Sali- 

 cornia. The proventriculus 

 is turgid with the latter. 

 Its glands are extremely 

 numerous, of a cylindrical 

 form, about 3 twelfths in 

 length. The epithelium, or 

 inner coat of the stomach, 

 is thick and tough, the two 



Vol. VI. 32 



