Dimarcusidae

Dimarcusidae is a family of triclads found mostly in freshwater habitats of caves, although at least one species, Rhodax evelinae, occurs in surface waters. Currently the family contains only seven species distributed in five genera, although the total number of species is thought to be much higher.

== Description == thumb|left|Copulatory apparatus of Hausera|Hausera hauseri showing the common ovovitelline duct (cod) perpendicular to the female genital duct (dgf) The morphological features uniting species of Dimarcusidae are related to the reproductive system. Their ovaries are located more posteriorly than in most triclads, which usually have them close to the brain. The penis in species of Dimarcusidae contains glandular elements and the common ovovitelline duct is perpendicular to the female genital duct.