5. Alto-cumulus informis (Plate [25]).
Characterized as more or less rounded cloudlets interspersed with ragged bits of cloud and occasionally with streaks of cirrus, the cloudlets showing no clear-cut outlines, but having distinct shadows. A. Cu. In.
6. Alto-cumulus nebulosus (Plate [26]).
Hazy alto-cumulus. A. Cu. Neb.
7. Alto-cumulus castellatus (Plate [28]). Turret cloud.
A high cloud resembling a number of tall narrow cumulus clouds on a very diminutive scale. The cloudlets show distinct shadows, are very opaque, and their upper margins are sharply defined. Vertical axes longer than the horizontal ones. A. Cu. Ca.
8. Alto-cumulus glomeratus (Plate [29]).
Characterized by the roundness and regularity of the cloudlets, which have sharp margins, cast distinct shadows, and have their axes about equal in all directions. A. Cu. Gl.
9. Alto-cumulus communis.