[3] Members of the order Lecithoepitheliata are distinguished from other flatworms by the presence of four nerve cords and the fact that the ovary forms a single structure that produces both the eggs (ovocytes) and nourishing yolk cells (vitellocytes).

In most other rhabditophorans, yolk cells, where present at all, are typically formed in glands derived from the ovaries, but separate from them, called vitellaria.

[5] Other diagnostic features of this order include the presence of a sharp stylet on the end of the penis, and a simple, unbranched, intestine.

[4] The order Lecithoepitheliata is usually classified as belonging to the clade Neoophora, a subgroup of rhabditophoran flatworms distinguished by the presence of ectolecithal eggs, i.e., yolk is stored outside the ovocytes.

[6] However, recent molecular studies have grouped Lecithoepitheliata (at least the family Prorrhynchidae) with the order Polycladida, which has endolecithal eggs, i.e., yolk is stored inside the ovocytes as in most animals.