Hofsteniidae is a family of acoels.

[1] This worm ranges in size from 100 μm for embryos to 500 μm for adults, and exhibits "whole-body regeneration" capability, where entire body parts regenerate when removed from the body.

[2] They have a simple nervous system and a bowel sac with no way out.

[3] There are three genera in the family Hofsteniidae.

[1] There are seven species in the family Hofsteniidae.