Secondary Forms of Clouds
Cirro-Cumulus is formed from cirrus or cirrostratus clouds when they are warmed gently from below. Cirro-Stratus clouds appear as whitish and usually somewhat fibrous veils, often covering the whole sky and sometimes so thin as to be hardly discernible. The Cumulo-Stratus is the form produced by the heaping together of a mountain-like mass of cumulus clouds.
Edwin J. Houston, The Elements of Physical Geography, for the use of Schools, Academies, and Colleges. (Philadelphia: Eldredge & Brother, 1891) 103