The family Dendrocoelidae is characterized by an unusual arrangement of the muscle layers of the pharynx. While in most planarians the inner musculature of the pharynx is composed of two muscle layers, one circular and one longitudinal, in Dendrocoelidae the circular and longitudinal fibers are intermingled, forming a mixed layer. Dendrocoelidae is the sister group of
Kenkiidae. Both families have an anterior adhesive organ, which is considered a
synapomorphy of the group. == Genera ==