Joshua Hughes Paul, Forest grove and canyon streams, Salt Lake City, The Deseret News Press, 1913, p. 203.

Caddis Flies. Have you ever turned over the flat rocks in the bed of swift-flowing canyon streams ? If so, you must have noticed, in summer, that to these rocks often cling many small tubes sometimes an inch long, composed of sand, or of small pebbles or of small sticks cemented or glued together. Fishermen call them rock rollers, and use the insect that is inside the case as a trout bait.