Primary Forms of Clouds: Cirrus and Cumulus
Cirrus cloud is a type of cloud composed of ice crystals and characterized by thin, wisplike strands, often accompanied by tufts. A Cumulus cloud is a cloud belonging to a class characterized by puffs, mounds or towers, with flat bases and tops that often resemble cauliflower.
Edwin J. Houston, The Elements of Physical Geography, for the use of Schools, Academies, and Colleges. (Philadelphia: Eldredge & Brother, 1891) 102