678 CYGNUS AMERICAXUS. 



Female in Winter. — The female is similar to the male, 

 but considerably smaller. An individual dissected by me, as 

 detailed in Mr. Audubon's work, had about forty lamellae on 

 each side of the upper mandible, about sixty inner and twenty- 

 two outer on each side of the lower. The width of the mouth 

 one inch five-twelfths. The diameter of the aperture of the 

 eyes five-twelfths, of that of the ears four-twelfths. The 

 heart three inches two-twelfths in length, two inches ten- 

 twelfths in breadth. The oesophagus twenty-six inches long, 

 only four-twelfths wide, but at the lower part of the neck 

 dilating to eight-twelfths ; the proventriculus an inch and 

 two-twelfths in breadth. The stomach, which is obliquely 

 situated, is an extremely developed gizzard, of an elliptical 

 form, two inches and a half in length, three inches and ten- 

 twelfths in breadth ; the right lateral muscle an inch and 

 three fourths, the other an inch and a third in thickness ; the 

 epithelium thick, dense, with two smoothish, considerably 

 concave grinding surfaces. There is a large pyloric sac, from 

 which the duodenum comes off. The intestine measures 

 eleven feet five inches in length. It first curves round the 

 edge of the stomach to the length of eight inches and a half, 

 reaching the sixth rib, then returns, enclosing the pancreas 

 to before the stomach, passes along the spine nearly to the 

 end of the abdomen, returns to the edge of the stomach, forms 

 a small loop, comes forward, then backward, forward, back- 

 ward, and forward, becomes anterior, curves parallel to the 

 duodenum to the seventh rib, passes backward, curving up 

 to the liver, returns, comes back, then stretches nearly to the 

 cloaca, where it becomes accompanied by the coeca, comes 

 forward on the right side to the anterior edge of the stomach, 

 and bends abruptly backwards, forming the rectum. There 

 are thus sixteen bends or eight folds. The average width is 

 half an inch. The rectum seven inches long, eight-twelfths 

 in width ; the coeca eleven inches long, for three inches only 

 two-twelfths wide, then expanded to from three-twelfths to 

 four-twelfths-and-a-half ; the cloaca of moderate size and 

 globular. 



The trachea, twenty inches in length, has at first a breadth 

 of nine-twelfths, gradually contracted to seven-twelfths, and 



