ABSTRACT
Piriform, round, rod-shaped, or ameboid; without conoid; without oocysts, spores, or pseudocysts; without or with subpellicular microtubules; without flagella; with polar ring and rhoptries; locomotion by body flexion, gliding, or — in sexual stages (in Babesiidae and Theileriidae at least) — by large axopodium-like "Strahlen"; asexual and probably sexual reproduction present; parasitic in erythrocytes and sometimes also in other circulating and fixed cells; heteroxenous, with merogony in vertebrate and sporogony in invertebrate; sporozoites with one-membraned wall; so far as known, the vectors are ticks; but the vectors of anthemosomatids are unknown.
