Mr. Y All R ELL on the Trachcce of Birds. 385 



The dift'erent species of Geese considered British, present 

 nothing remarkable in their tracheae, the Egyptian Goose alone 

 excepted. The male of this bird possesses a bony enlargement 

 at the bottom of its windpipe, in size equal to that marked («) in 

 Tab. XV. Systematic authors seem to agree in placing this 

 bird at the bottom of the list of the Geese, where it appears to 

 occupy its proper situation. 



Combining as it does some of the characters common to those 

 birds and the true Ducks, it becomes a very natural link between 

 them ; and with a few observations on an arrangement of the 

 British species of the latter portion of this family, founded upon 

 internal as well as external conformation, I shall close this 

 paper. 



The first division of true Ducks will contain the Shielduck, 

 ]\Iuscovy, Wild Duck, Gadwall, Shoveler, Pintail, ^Vigeon, 

 Bimaculated Duck, Garganey, and Teal, — all of which will be 

 found to have the following characters in common. Externalljr 

 they exhibit considerable length of neck : the wings are also 

 long, reaching to the end of the tail ; the tarsi somewhat round ; 

 the hind-toe free, or having no pendent lobe. In habits they 

 may be stated generally as frequenting fresh-water, but passing 

 much of their time on land, feeding in ditches and about the 

 shallow edges of pools on aquatic plants, insects, worms, and 

 occasionally fish, taking their food at or near the surface ; pos- 

 sessing great powers of flight, but seldom diving, unless pur- 

 sued. Of their internal soft parts, the stomach is in the greatest 

 degree muscular, forming a true gizzard ; the intestines long, the 

 caecal appendages from six to nine inches in length in the larger 

 birds, and decreasing only in proportion to the size of the spe- 

 cies. Of the bones it may be observed, that the ribs are short, 

 extending but little beyond the line of the posterior edge of the 

 sternum ; the keel of the breast-bone deep, aftbrding great ex- 



3 D 2 tent 



