790 SYSTEMATIC SYNOPSIS.— PYGOPODES. 
front and sides of the head. A patch of sharp white streaks on the throat, and another larger 
triangular patch of the same on each side of the neck lower down, the two last nearly or quite 
meeting behind, separate in front. Sides of breast striped with black and white. Entire upper 
parts, wing- coverts, inner secondaries, and sides under the wings, glossy black ; all except the 
sides thickly marked with white spots; those of the scapulars, tertials, and middle back, large, 
square, and regular; those of other parts smaller, oval, smallest on rump, most numerous on 
wing-coverts. Upper tail-coverts greenish-black, immaculate. Wing-quills brownish-black, i 
lighter on inner webs. Under surface of wings, axillars, and under parts generally from the 
neck, pure white ; the lower belly with a dusky band. The white throat-patch consists usually 
of five or six streaks ; in 
this, as in the lateral 
neck-stripes, the individ- 
ual feathers are broadly 
black, with sharp white 
edges toward their ends. 
The texture of these 
feathers is peculiar, — the 
outer surface is hollowed, 
with raised edges of spe- 
cially firm, smooth, pol- 
ished character, so that 
these patches may be felt 
as well as seen. The 
white spots on the back 
occur in a pair on each feather near its end, their aggregation in any region being therefore 
determined by the size of the feathers themselves. Young : Bill smaller tliau in the adult, 
bluish- white, with dusky ridge. Iris brown. Crown and hind neck dull brownish-black ; 
other upper parts similar, but the feathers, especially of the fore back, with light gray edgings. 
Primaries black, with brown inner webs. Tail-feathers with gray tips. Traces of lighter and 
darker liueation on sides of breast. Sides of head mottled with ashy and whitish ; chin, throat, 
neck in front, and whole under parts, white. Dimensions: length 31 to 36 inches; extent 
about 52.00; wing 12.50 to 14.25; bill 2.75 to 3.00 along culmen; gape 4.00 to 4.25; height 
at nostrils, about 0.80; wddth there about 0.40: tarsus 3.00 to 3.50; middle toe and claw 
4.25 to 5.00. Inhabits the Northern Hemisphere. In winter, generally dispersed in the U. S. ; 
breeds in portions of the U. S. and thence northward. Eggs 2, 3.50 X 2.25, elongate and 
pointed, dull greenish -drab, with dark brown spots. Young covered with stiffish black down. 
841. C. t. a'damsi. (To Dr. C. B. Adams.) Yellow-billed Loon. Larger than C. torquatus, 
with the bill rather larger and somewhat differently shaped and colored. Bill about equalling 
head, longer than tarsus, much compressed, tip very acute, not at all decurved, the culmen 
being almost perfectly straight, as the commissure also is. Gonys straight or nearly so to the 
angle, which is very prominent. (Fig. 530 shows the shape of the bill better than it does that 
of No. 840, for which it is intended.) Frontal antisB reaching beyond middle of nostrils. Bill 
light yellowish horn-color, only dusky at base. Head aiid neck deep steel-blue, with purplish 
and violet reflections, glossed only on the cervix with green. Throat-patch of white streaks 
smaller than in torquatus, but the individual streaks larger, as are those of the neck-patches. 
White spots of upper parts larger than in torquatus, longer than broad instead of square on the 
scapulars and tertials. Bill along culmen 3.50 to 3.75; along gape 5.00 to 5.25; height at 
nostrils 0.95 to 1.10; width 0.40 to 0.50 ; tarsus 3.50 ; outer toe 4.65 to 5.10. General dimen- 
sions somewhat exceeding those of torquatus. Arctic America, common; perhaps specifically 
distinct from the last. 
