- ANATID A, — SUBFAMILIES. 187 
and yet an impartial reader must -have perceived our 
anxiety, on many occasions, to state all those points 
upon which we entertain doubts, that they may be 
decided by others, rather than ourselves. And it is for 
the very purpose of doing this, in the present instance, 
that we have entered much more into the analogies of 
this order than we intended, or than our limited space 
will sanction. The objections, therefore, to the above 
table are these:—It has been seen among all the groups 
of the Insessores, and even among quadrupeds, that a 
broad and flat muzzle is one of the primary indications 
of the fissirostral type; it therefore would seem to 
follow, that that type, in the present family, must be 
the ducks, and not the pelicans: these latter, again, as 
in the genus Carbo, have that peculiar rigidity of tail 
which indicates the scansorial, and. not the fissirostral 
structure: most of these birds, also, have crests upon 
their heads; a further evidence of their analogy to the 
Rasores, and not to the Fissirostres. To these facts, 
and the inferences that might thus be drawn from them, 
we should reply, that this interchange of characters in 
the aberrant groups of an aberrant circle (for such is the 
Natatores among the orders of birds) is by no means 
uncommon, and that we have repeatedly adverted to it 
in other instances where the circle of affinities were even 
stronger than in this. A broad and flat bill is, indeed, 
one of the primary distinctions of the natatorial type, 
but it is not the only one; and when we finda pre- 
ponderance of the characters of any given type found 
in any one particular family, it seems to us that we 
must look to the coincidences, and not to the exceptions. 
The same may be said regarding the stiff tails of the 
‘Pelicanide: this is the only scansorial character they 
have borrowed, as it were, from the Anatide, who, in 
‘Yeturn, seem to have assumed the flat depressed bill of the 
fissirostral Pelicanide. On no other principle, in short, 
_ than the one above stated, can we possibly account for — 
this singular combination of opposite characters found in 
the two extreme groups of the Natatores,—the Anatide 
