Mrazekia Léger & Hesse 1916

M. cyclopis occurs in adipose and connective tissues of Acanthocyclops americanus (Copepoda, Cyclopidae), is monomorphic, diplokaryotic throughout life cycle; merogony is probably by binary fission or plasmotomy of small plasmodia; sporogony is disporoblastic, in direct contact with host cell cytoplasm; spores, 7-8 x 1.5 µm, cylindrical, rodshaped, slightly bent with blunt ends, without taillike prolongations; endospore is thick, exospore composed of alternating dense and lucent layers; polaroplast composed of an anterior region of tightly compressed lamellae, giving way to more looselyarranged lamellae; polar tube straight, wide anterior, manubriumlike part, of which the posterior end is prominently enlarged; bent anteriorly, forming an angle to the longitudinal axis of the spore; type species M. argoisi in the fat body of Asellus aquaticus (Isopoda, Asellidae).