PALMIPEDES. 



265 



Kig. 131.— Sternum of Tesl. 



been killed here. Most of these birds are very fine eating-, the Scaup least so, and feed (excepting that s; ecies) 

 principally on vegetable diet. Their coeca are largfer than in nearly .ill of the foregoing.] 



The Ducks of our second division, wherein the back toe is not bordered by a membrane, have a 

 more slender head, the feet less broad, the neck not so long, the bill more even, the body not so thick : 



they walk better, and feed on aquatic plants and seeds, as well as 

 on animal diet, [as indeed do also the preceding, though generally 

 to a less extent]. It appears that their tracheal labyrinths con- 

 sist of a homogeneous bony and cartilaginous substance, [which 

 forms a simple vesicle. They all moult twice in the year, the 

 males attaining, by actual change of feather about midsummer, a 

 garb more or less similar to that of the females. They have a con- 

 siderable dilatation of the esophagus, and large ccEca]. 



These likewise admit of some subdivisions, [though considerably 

 less strongly marked than the foregoing]; and firstly, we may 

 distinguish that of 



The Shovellers {Rhyncaspis, Leach), — 

 The long beak of which is remarkable for its upper mandible 

 forming a perfect half-cyliuder, widened at the end. The lamallae 

 are so long and delicate that they resemble cilia;. These birds feed 

 on small worms, which they obtain from the mud at the edge of 

 brooks, [and are merely true Ducks with the bill a little modified]. 



The Common Shoveller (An. clypeata, Lin.), is a very beautiful Duck, with green head and neck, white breast, 

 rufous flanks, brown back, and wings varied with white, ash-grey, green, brown, &c., which visits us [principally] 

 in the spring. Its flesh is excellent, and tracheal labyrinth small, [the intestines remarkably narrow and elongated]. 

 It is the Chencrotcs of Pliny. 



An Australian species (An. fascial a, Shaw), is remarkable for the edge of its beak being prolonged on each side 

 into a hanging membranous flap. [The Shovellers grade into the ordinary Ducks by a succession of species, allied 

 to the British Gargany Duck, which latter retains much of the same character of plumage and colouring.] 



The Shieldrakes {Tadoraa, Leach) — 

 Have the bill very much flattened towards the end, with a projecting boss at the base. [These birds 

 are the most duck-like representatives of an extensive group, found chiefly in the southern hemisphere, 

 and intermediate in their general characters to the present group of Ducks with unlobatcd hind-toe, 

 and the Geese, but exhibiting none of the essential characters of the former. Like the Ducks, they have 

 always a brilliant speculum of metallic colouring on the wing, and an inflated vesicle, in some single, 

 towards the divarication of the bronchi : but they are exclusively vegetable feeders ; the male guards 

 the nest, and protects his brood, uttering with outstretched neck a hissing sound at any intruder; 

 their plumage is moulted but once a year, and undergoes no seasonal change of colour, being generally 

 ahke in both sexes, or, when different, the male is white, as in certain Geese ; and lastly, they have a 

 gait very diflferent from that of the Ducks, all of them standing high upon the legs, and tlieir young 

 are at first pied, unlike those of other Lamcllirostres. In all that we have examined, the intestines are 

 particularly long and slender. Their subdivision is not easy ; and the common Shieldrake and Egyptian 

 Goose, or Bargander, may be cited as characteristic examples : the wings of most are very similar. 



The Common Shieldrake (An. tadorna, Lin. ; T. vulpanser, Auct.).— White, with a green head and neck, a cin- 

 namon-brown cincture round the breast, and black streak down the belly ; the wing variegated with black, white, 

 rufous, and green. Common on the shores of the North Sea and of the Baltic, where it nestles in the downs, 

 generally in deserted Rabbit burrows, [and not rare on the British coasts, subsisting on fuci]. The trachea 

 swells into two nearly similar osseous capsules at its divarication. 



[Another, of eastern Europe and Asia, the Ruddy Shieldrake (7*. rutila), has been known to stray westward as 

 far as Britain. It has more the characters of a Goose, and chiefly inhabits the banks of large rivers. Wing like 

 the common species, the rest of its plumage chestnut-rufous, whitish on the head and neck.] 



Some Ducks of this second division have naked parts on the head, and often likewise a boss at the 

 base of the beak ; as, 



The Musk Duck (.1. moschata, Lin.).— Originally from America, where it is still found wild, and is observed to 

 perch upon trees ; it is now very common in our poultry-yards, where it is reared on account of its size. It readily 

 hybridizes with the common species, [producing infertile hybrids]. Its capsule is very large, circular, vertically 

 flattened, and on the right side only. [Its legs are very short, both sexes are alike in plumage, the male guards 

 the nest and brood, and we consider it to be an extreme modification of the group of Shieldrakes.] 



