It is needless here to enlarge upon the characters peculiar to the ANATOIDEAE, the 'duck tribe,' in its widest sense, since few groups are better known to the general reader. It is one of the best circumscribed super-families of recent birds, and its distinguishing characters so well marked externally, that nobody fails to recognize any member at an instant, be it a swan, a goose, a duck, or a merganser, and most of the systematic names invented for the group, as Lamellirostres, Lamelloso-dentali, Serrati, Dermorhynchi, etc. --have been derived from the soft-skinned bill with the curious lamellae teeth. Most of the species take their food under water, and, when the head is raised, the water runs out between the lamellae, which act like a sieve in retaining the food, which led to the invention of the English word ' sifters,' as an equivalent. In some forms the lamellae are shortened and thickened so as to enable them to act as teeth in nipping off grass, as, for instance, in the geese, while in the mergansers they are modified into retrorse hooks, which serve to prevent the slimy fish from slipping away. Some of the more important anatomical characters have been mentioned under the foregoing super-family.
Ducks, and their allies, are found all over the globe. Man has found them whereever he went, and he has seen them flying northwards at the northernmost point he has reached.
The first form to meet us of the 'duck tribe,' in its widest sense, is one of those remarkable extinct birds which formerly inhabited the islands of New Zealand, and which lost their power of flight through disuse of that faculty, and consequent degeneration of the parts. Though originally described in connection with the Moa remains, and found together with them, the Cnemiornis, as it was called by Owen, has nothing to do with Dinornis, or the Struthious birds at all; its ilia and ischia are united behind, the sternum has trace of a keel, and the palate is esmognathous.
