The morphology and life history of a cephaline gregarineHirmocystis lepropi n. sp. from the gut of the beetle,Lepropus sp. are described. The parasite passes through an intracellular phase of development before reaching the trophozoite stage. The trophozoite has a length of 77·5 to 580·0μ, and has an epimerite, a protomerite and a deutomerite in its body. The gametocysts are ovoidal bodies and give rise to spores. Each spore measures 6·0×4·0μ.