684 CYGNUS AMERICANUS. 



which it curves to above the stomach, and proceeds nearly 

 straight to the end, forming in all sixteen curves. The rec- 

 tum is ten inches in length, eleven-twelfths in breadth, and 

 at the end is expanded into a cloacal dilatation, an inch and a 

 half in width. The cceca are fifteen inches long, for four 

 inches and a half only three-twelfths in breadth, then enlarg- 

 ing to one inch, and toward the end contracting to four- 

 twelfths. The right lobe of the liver is five inches in length, 

 the left three inches, the gall-bladder elliptical, an inch and 

 a half. The spleen is only ten-twelfths in its greatest dia- 

 meter. The heart two inches and ten-twelfths in length, an 

 inch and ten-twelfths in breadth. 



The trachea, formed of about two hundred and eighty 

 flattened rings, is at first nine-tAvelfths in breadth, then con- 

 tracts to six-twelfths, and becoming round enlarges to seven- 

 twelfths, and entering the cavity in the crest ef the sternum 

 to the distance of three inches, forms a vertical loop, returns, 

 curves in the furcula, and enters the thorax to the distance of 

 two inches. The syrinx is formed of five united rings, and is 

 compressed, being half an inch in breadth, and an inch in 

 depth. Appended to the last half ring on each side is a nar- 

 row membrane terminating in a very slender half ring, and 

 external to the large membrane between the last tracheal and 

 first bronchial half ring. The bronchi are very short, an inch 

 and a half in length, at first compressed, half an inch in 

 height, then round, and half an inch in diameter, finally 

 cylindrical and narrower. The rings are slender, incomplete, 

 a few anchylosed ; the right bronchus with twenty, the left 

 twenty-four. 



The nostrils are linear-oblong, nearly half an inch in 

 length, situated beyond the middle, in the fore part of the 

 oblong nasal space. The eyes are small, their aperture only 

 four-tAvelfths and a half. That of the ear round, four-twelfths 

 in diameter. The legs are short, very stout ; the tibia very 

 muscular, bare for an inch and a quarter ; the tarsus short, 

 considerably compressed, reticulated with angular scales, of 

 which the anterior are larger and rounded ; the hind toe very 

 diminutive, with a slight thickened lower margin, the middle 

 toe longer than the tarsus ; the outer considerably longer than 



