500 Mr. N. A. Vicors on the Natural Affinities 
and most typical group of the family, which accords with M. Tem- 
minck's first section of ** Canards proprement dits," still approaches 
more closely to the land-birds than the birds which follow : the 
species swim with ease, and even dive, but the latter faculty they 
seldom exercise unless when pursued. Their food is also less ex- 
clusively marine than that of the succeeding groups, being com- 
posed of vegetables, grains, and insects, in addition to fish*. This 
division, consisting of many prominent forms, of which A. arbo- 
rea before mentioned, A.tadorna, boschas, clypeata, penelope, and 
querquedula may be considered types, is distinguished from the 
remainder of the ** Canards proprement dits" of M. Temminck, by 
thehind toe being entire, orfreefrom the lobated membrane which 
is attachedto the hind toe of these last. ‘This character of the lo- 
bated membrane, which is of considerable importance as pointing 
out the approach of the birds in which it is found to the more typi- 
cal oceanic families, prevails in all the remaining groups of the 
present family. It is strongly conspicuous in Mergus, Linn., the 
next division that appears to follow: and we consequently find 
that the species of that genus carry the powers of swimming and 
diving to the greatest extent, making use of their wings also in 
their progress through the water; and at the same time exhibiting 
a constrained and embarrassed mode of walking, in consequence 
of the backward position of the legs. Itthus forms the passage to 
the succeeding family of Colymbide. In the shape of its bill, which 
is slender and partially compressed, it exhibits a distinct form in 
its own family: but still, by means of the bill of an intervening 
* « Les Canards dont le pouce n'est point bordé d'une membrane, ont la 
téte plus mince, les pieds moins larges, le cou plus long, le bec plus egal, le corps 
moins epais; ils marchent mieux; recherchent les plantes aquatiques et leur graines, 
autant que les poissons et autres animaux." Cuv. Regne Anim. i. p. 536.—'* Ceux 
se submergent rarement dans d'autres cas que lorsqu'ils sont poursuivis.— Leur nour- 
riture se compose indistinctement de vegetaux, de graines ou d'insectes et de poissons." 
Temm. Man. p. 831-2. | 
species, 
