The singular and ingenious little cases

Mary E. Murtfeld & Clarence Moores WeedOutlines of Entomology, Jefferson, Tribune Printing Company, 1891, p. 126.

The female flies lay their eggs upon water plants, and the aquatic larvae attract much attention on account of the singular and ingenious little cases which they construct for the protection of their soft bodies. These are made of silk, and to the outside are attached small pebbles, coarse sand, or bits of sticks or leaves, giving them very peculiar and often beautiful forms. Some species make their cases entirely of silk, and of a very elongated come shape.