Bill, in the Goatsuckers and Swifts, small; mouth large; in the Hummingbirds, bill long, slender, needle-like; wings and tail variable; feet, in all three groups, small and weak. Color, in Goatsuckers, mixed brown, buff and black; in Swifts, black and white; in Hummingbirds, usually shining green above with resplendent throat-patches of varied hues.
Family 44. GOATSUCKERS, ETC. Caprimulgidæ.
Feet usually small and weak; toes, three in front, one behind; middle toe-nail pectinate or combed; bill small; mouth very large and usually beset by long bristles.
Family 45. SWIFTS. Micropodidæ.
Bill small, triangular when seen from above; mouth large, no bristles; tail variable, in Chætura with projecting spines; wings long and narrow; feet small and toes short; plumage usually dark.
Family 46. HUMMINGBIRDS. Trochilidæ.
Bill long and slender; feet slender; wings large and pointed; tail exceedingly variable, often assuming the most striking shapes.