Haemosporina (subclass Coccidia, order Eucoccidia) A suborder of protozoa in which gametocytes develop independently, i.e. syzygy does not occur. More than one host species is required for the completion of the life cycle. The sexual stages occur within an insect host, while asexual reproduction occurs in a vertebrate host. There are three families, and several genera, including the malarial parasite Plasmodium.

Coccidia (subphylum Sporozoa, class Telosporea) A subclass of parasitic protozoa which grow and reproduce inside the cells of an animal host. There are two orders, and many species.