BIRDS—PICID AE-PICUS. 
83 
PICUS, Linnaeus. 
Picus, Linn. Syst. Nat. 1748. * • 
Bill equal to the head, or a little longer ; the lateral ridges conspicuous, starting about the 
middle of the base of the bill; the basal elongated oval nostrils nearer the commissure; the 
ridges of the culmen and gonys acute, and very nearly straight, or slightly convex towards the 
tip ; the bill but little broader than high at the base, becoming compressed considerably before 
the middle. Feet much as in Campephilus ; the outer posterior toe longest; the outer anterior 
about intermediate between it and the inner anterior ; the inner posterior reaching to the base 
of the claw of the inner anterior. Tarsus about equal to the inner anterior toe ; shorter than 
the two other long toes. Wings rather long, reaching to the middle of the tail, rather rounded ; 
the fourth and fifth quills longest; the quills rather broad and rounded. 
In the genus Picus, as characterized above, are contained several subdivisions more or less 
entitled to distinct rank, and corresponding with peculiar patterns of coloration. Thus, taking 
the P. villosus as the type, P. borealis has proportionally much longer primaries ; the spurious 
primary smaller ; the hill is considerably more attenuated, and even concave in its lateral 
outlines. The wings are still longer in P. albolarvatus. 
The species may be arranged as follows : 
A. Black above, and white beneath. Two white stripes on the side of the head, with black 
ear covers. Wings spotted with white. 
Trichopicus, Bp.—Middle of back streaked longitudinally with white. Beneath white, 
without spots. A narrow red nuchal band. 
1. Outer tail feathers pure white. Length about 1 0 inches. 
Wing coverts and innermost secondaries conspicuously spotted with 
white. P. villosus. 
Wing coverts and innermost secondaries nearly uniform black, without 
spots. P. harrisii. 
2. Outer tail feather white , with black transverse bands. Length about 65 inches. 
Wing coverts conspicuously spotted with white. P. pubescens. 
Wing coverts and innermost secondaries nearly uniform black. .P. gairdneri. 
Dyctiopicus, Bp.—Middle of back handed transversely with white and black. Beneath 
white, with black spots on the side. 
Entire crown and nape of male red, spotted with white. Feathers at the 
base of hill brown... P. scalaris. 
Crown black; nape red; both spotted with white. Feathers at base of 
hill white. P. nuttalli. 
B. Black above and white beneath. Sides of body with black spots ; sides of head black, 
with a white auricular patch. Wings lengthened. 
Phrenopicus, Bp.—Back handed transversely with white. 
A narrow lateral line of red above the auricular patch. P. borealis. 
C. Xenopicus, Baird.—Entirely black, with white head. Wings lengthened. 
A white patch at the base of the longer primaries. P. albolarvatus. 
The following table will serve to exhibit the comparative measurements of the different species 
of Picus found in the United States. 
