Dugesiidae

Dugesiidae is a family of freshwater planarians distributed worldwide (except Antarctica). The type genus is Dugesia Girard, 1850.

==Description== All species of Dugesiidae live in freshwater environments and have a dorsoventrally flattened body. The head usually has a somewhat triangular shape and has two eyes (except for some subterranean eyeless species). The main differences between Dugesiidae and other freshwater planarians are related to the anatomy of the eyes and the copulatory apparatus. The eye cup in Dugesiidae is composed of several retinal cells, while in other freshwater planarians they are composed of a single cell.