316 THE HORNED GREBE. 



number of turns being twelve. Its length is 33 inches; its width |- inch at 

 the upper part, towards the rectum only 3 twelfths. The coeca are 2 inches 

 long, 2 twelfths in breadth, uniform, unless at the base, where they are 

 narrower; their distance from the extremity 3 inches. The cloaca is 

 globular, 1^ inches in diameter. 



The trachea is 94 inches long, of the nearly uniform width of 3i twelfths, 

 unless at the lower part, when it is narrowed to 2 twelfths; flattened in its 

 upper half, and compressed in the lower; the rings moderately firm, 180 in 

 number. The Grebes differ from almost all other birds in having the 

 bronchial rings complete and firmly ossified. In the present species, they 

 are only 8 in number, the remaining part of the bronchi being membranous. 

 There are the usual cleido-tracheal muscles; the sterno-tracheal, part of 

 which is continuous with the lateral muscles, but the inferior portion 

 distinct, and attached to several of the rings; there is also a single pair of 

 inferior laryngeal muscles. 



The jugular veins are of vast size, and toward the lower part of the neck 

 form an immense dilatation; that of the left side being distended with 

 coagulated blood to 9 twelfths of an inch, and so continuing until it enters 

 the heart. The other is \ inch in breadth. In this respect there seems to 

 be an analogy to the diving mammifera, such as the seals and dolphins. 



THE HORNED GREBE. 



Podiceps cornutus, Linn. 



PLATE CCCCLXXXL— Male and Young. 



The period at which this little Grebe makes its first appearance, after the 

 breeding season, on the waters of the Western States, such as the Ohio, the 

 Mississippi, and their numerous tributaries, is the beginning of October, 

 when I have seen them arriving and passing onward on wing at a consider- 

 able height in the air, following the course of the streams. The generally 

 received idea that birds of this genus perform their migrations on the water, 

 is extremely absurd. I have already offered some remarks on this subject, 

 but as too much cannot be said, when an erroneous notion extensively 



