NORTHERN THREE-TOED WOODPECKER. 43 
bills, and the third for the three-toed species indis- 
criminately. The onty foreign three-toed species in our 
collection, the beautiful Picus Bengalensis of authors, 
( Picus tig a of Horsfield,) widely spread through tropical 
Asia and the adjacent islands, and, though long since 
known, always ranked as four-toed, has the bill precisely 
similar to the four-toed species, being even remarkably 
compressed, and very sharp on the ridge. 
The male northern three-toed woodpecker is ten 
inches long, and sixteen in extent ; the bill measures 
one inch and a quarter, is of a blackish lead colour, 
bluish white at the base of the lower mandible ; it is 
very broad at base, cuneiform and obtuse at tip, and 
much depressed throughout, the ridge being very much 
flattened : both mandibles are perfectly straight ; the 
upper pentagonal, the lower obtusely trigonal ; the 
tongue is somewhat shorter than that of other species 
of the genus ; the bristly feathers at the base of the bill 
are very thick and long, a provision which Nature has 
made for most arctic birds ; in this they measure half 
an inch, and are blackish, white at base, somewhat 
mixed with reddish white; the irides are bluish black; 
the whole head and neck above and on the sides, back, 
rump, scapulars, smaller wing and tail-coverts, consti- 
tuting the whole upper surface of the bird, of an uniform, 
deep, glossy black, changing somewhat to green and 
purple, according to the incidence of light ; the feathers 
of the front are tipped with white, producing elegant 
dots of that colour (which perhaps disappear with age ;) 
the crown of the head is ornamented with a beautiful 
oblong spot one inch in length, and more than half an 
inch broad, of a bright silky golden yellow, faintly 
tinged with orange, and the feathers in this place very 
fine, and somewhat rigid ; they are black at their base, 
and marked with white at the limits of the two colours ; 
the base of the plumage elsewhere is uniformly plumbeous 
ash : each side, from the corner of the mouth, arises a 
broad white line, forming a white space before the eye, 
prolonged on the neck ; beneath this there is a black 
one, which, passing from the base of the lower mandible. 
