270 DUCK. 



Pato real 6 grande, Greater Royal Duck ; seen single, or in pairs ; 

 sometimes twenty together, or thirty, roost at night on high trees ; 

 lays in September from ten to fourteen eggs, in the hollow of a 

 tree, on a bed of feathers from the breast of the male. The 

 windpipe of the male is stout, nearly equal in diameter, but a 

 trifle smaller towards the bottom ; the bony arch, as in others, 

 finishes the bottom part, and appears as if furnished with rings, 

 but they are not moveable, as in the rest of the trachea ; the 

 orbicular labyrinth is attached to the side of it ; this is not smooth 

 on the surface, as in the Pintail and Wigeon, but universally 

 rough and irregularly furrowed, with fine indented lines : the 

 opposite side of a pear shape, and placed obliquely, with the point 

 lowest, but is flattened considerably on the surface ; the bony 

 arch is on this side smooth, having no appearance of rings, and 

 is bent at a small angle from the trachea, though it constitutes 

 a continuance of it. In old birds the bony labyrinth is more 

 rounded and larger, but still retains the roughness on the surface ; 

 in a very old subject, furnished to me by the late Mr. Boys, the 

 labyrinth was not only much larger, but nearly globular, and 

 the bony arch quite smooth, yet finely granulated, and faintly 

 wrinkled, and the texture more bony;* that figured by Dr. Bloch, 

 in the Berlin Trans.-\ appears by much too large, but may not be 

 faulty, for in case his figure was taken from a foreign specimen, 

 and supposing the Muscovy Duck to arrive at twice the size of 

 those in England, and which they are said to do, no doubt but the 

 labyrinth and trachea would be in due proportion. 



41— NILOTIC GOOSE. 



Anas Nilotica, Ind. Om. ii. 846. Gm. Lin. i. 508. Hasselq. It. 365. 36. Id. Voy. 201. 



Bauk, Baw Goose, Pocock. Trav. i. 210 ? 



Nilotic Goose, Gen. Si/n. vi. 488. Bruce, Trav. App. 154 ? 



SIZE between the Pintail Duck and Common Goose, but stands 

 higher on the legs. Nail of the bill hoary, the margin of it bounded 



* See Lin. Trans, iv. p. 113. pi. xvi. f. 5. 6. t Schr. d. Berl. Nat. iii. s. 372. t. 7. f. 6. 



