Wikipedia
Dileptus
Dileptus is a genus of unicellular ciliate protists in the class Litostomatea. Species of Dileptus occur in fresh and salt water, as well as mosses and soils. Most are aggressive predators equipped with long, mobile proboscides lined with toxic extrusomes, with which they stun smaller organisms before consuming them. 13 species and subspecies of Dileptus are currently recognized.
Dileptus species have served as model organisms, used in the study of ciliary patterns, ontogenesis, conjugation and food acquisition