The taxonomic position of this genus is unclear and it may be related to the gregarines or to the coccidians.
They possess a smooth surface lacking any grooves or folds.
The pellicle appears to be trilaminar and longitudinal microtubules lie deep to it.
The parasite infects the gastrointestinal tract and is presumably transmitted by the orofaecal route but the details of this mechanism are presently unknown.
Species in this genus infect the polychete worm Scoloplos armiger.