Monocystis

Monocystis
Scientific classification
Domain: Eukaryota
Clade: Sar
Clade: Alveolata
Phylum: Apicomplexa
Class: Conoidasida
Order: Eugregarinorida
Family: Monocystidae
Subfamily: Monocystinae
Genus: Monocystis
Stein, 1848

Monocystis (Gr., monos, single + kystisis, bladder) is a genus (the type of the family Monocystidae) of acephaline gregarines (subclass Gregarinasina) not having the protoplasm divided into segments by septa and including internal parasites of invertebrates (as M. agilis of the reproductive system of earthworms).