Mr. YAnnELL on the Tracheæ of Dirds. 385 
The different species of Geese considered British, present 
nothing remarkable in their tracheæ, 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 (a) in 
Tas. XV. Systematic authors seem to agree in placing this 
bird at the bottom of the list of the Geese, where it — 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 Sfüelduck, 
Muscovy, Wild Duck, Gadwall, Shoveler, Pintail, Wigeon, 
Bimaculated Duck, Garganey, and Teal,—all of which will be 
found to have the following characters in common. Externally 
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 
cæcal 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, affording great ex- 
3 D2 tent 
