TYPES OF HIGH CLOUDS
Cirrus: Thin, white, featherlike clouds in patches or narrow bands; composed entirely of ice crystals of varying size; larger crystals often trail down a great vertical extent in well defined wisps called "mare's tails."
Cirrocumulus: Thin sheet of cloud with individual small white puffs appearing as flakes or patches of cotton, usually composed of ice crystals, but may be composed of highly supercooled water droplets, or a mixture of both; likely to be confused with altocumulus.
Cirrostratus: Thin transparent, whitish cloud layer appearing as a sheet or veil; diffuse, or sometimes partly fibrous; widespread high cloud composed of ice crystals and usually covers a large portion of the sky. Sometimes halos around the sun or moon are the only indication of its presence.