Illustration of a cirrocumulus cloud, a large, white patch or tuft without a gray shadow. Composed of supercooled liquid droplets (if they freeze, becomes cirrostratus - cirrocumuli are short lived) Each cloudlet appears no larger than a finger held at arms length. It occurs in patches or sheets, organized in rows like other cumulus, but since they are so small, cirrocumulus patches take on a finer appearance, sometimes referred to colloquially as "herringbone" or "mackerel"
Illustration of Scomberomorus cavalla (King Mackerel)
Illustration of Scomberomorus munroi (Australian Spotted Mackerel)