PALLAS! DIPPER. 349 
bent upwards, notched, and with its edges bent in, and finely 
denticulated from the middle; but more especially by their 
long, stout, perfectly smooth tarsi, with the articulation ex- 
posed, a character which is proper to the order of waders, of 
which they have also the habits, nay, are still more aquatic 
than any of them. Their plumage also being thick, compact, 
and oily, is impermeable to water, as much so as that of the 
most decidedly aquatic webfooted birds ; for when dipped into 
it, that fluid runs and drops from the surface. Their head 
is flat, with the forehead low and narrow ; the neck is stout ; 
the body short and compact; the nostrils basal, concave, lon- 
gitudinal, half covered by a membrane; tongue cartilaginous 
and bifidattip. Their wings are short and rounded, furnished 
with a very short spurious feather, and having the third and 
fourth primaries longest; the tail short, even, and composed 
of wide feathers; the nails large and robust ; the lateral toes 
are subequal, the outer united at base to the middle one, the 
hind toe being short and robust. The female is similar to the 
male in colour, and the young only more tinged with reddish. 
They moult but once in the year. 
These wild and solitary birds are only met with singly, or 
in pairs, in the neighbourhood of clear and swift-running 
mountain streams, whose bed is covered with pebbles, and 
strewed with stones and fragments of rock. They are remark- 
ably shy and cautious, never alight on branches, but keep 
always on the border of the stream, perched, in an attitude 
peculiar to themselves, on some stone or rock projecting over 
the water, attentively watching for their prey. ‘Thence they 
repeatedly plunge to the bottom, and remain long submerged, 
searching for fry, crustacea, and the other small aquatic 
animals that constitute their food. They are also very destruc- 
tive to mosquitoes, and other dipterous insects, and their aquatic 
larvee, devouring them beneath the surface. They never 
avoid water, nor hesitate in the least to enter it, and even pre- 
cipitate themselves without danger amidst the falls and eddies 
of cataracts. Their habits are, in fact, so decidedly aquatic, 
