340 NATATORES. 



wild duck ; they have the bill more or less turgid or enlarged 

 at the basal part of the upper mandible ; the wings very 

 hollow, and both these and the tail stiff, and fit for action 

 under water. They dive much, seldom resort to fresh waters^ 

 and feed chiefly upon shelled mollusca, which they procure 

 by diving. Their flesh has a rank and fishy flavour ; and 

 on that account it is allowed to Roman Catholics in Lent 

 and on meagre days. Their breeding places are little known ; 

 and it has not been ascertained that any of them breed in 

 the British Islands.* 



THE BLACK SCOTER (Oidemio, nigrci). 



The length of this species is about twenty-two inches, the 

 breadth about twenty-four, and the weight from two pounds 

 and a half to three pounds. The plumage is entirely black, 

 without any wing spot. The upper mandible has an in- 

 distinct knob at the base, which is yellow, sometimes with 

 a reddish tinge, and the yellow is produced on the middle 

 of the bill beyond the knob, but it does not extend to the 

 tip. The rest of the bill is black or dusky. The orbits of 

 the eyes are yellow; the irides brown; the tarsi and toes 

 dusky, and the webs black. The tail is wedge-shaped at 

 the extremity, very stiff, and contains sixteen feathers. 

 The mark of a nail on the tip of the upper mandible is 

 wanting, as well as the wing spot. The female is rather 

 smaller, has the knob at the base of the upper mandible still 



* In all the diving-ducks, which feed principally upon shelled molluscs, 

 and on the roots of tough marine plants, as Vallisneria, the gizzard is of 

 enormous si/e smd density, and its internal lining is thick and leathery 

 it is preeminently constructed for crushing the shells of molluscs, by a 

 grinding action. In general, the flesh of these birds is rank, but the 

 can vass-1 mrkcd duck of America (Anas vallisneria), which fattens upon 

 the rods of a long grass-like' water-weed, is unrivalled for tenderness 

 and delicacy of .flavour. Most, if not all, the British diving-ducks are 

 natives of North America, as well as Northern Europe. M. 



