Pre-sporoblasts protruded to form buds from the plasmodial membrane that apparently separated to form electron-dense sporoblasts that lay in direct contact with the host cytoplasm(Fig. 5A). Sporoblasts underwent direct development to mature, electron dense and oval spores. The spores contained a single nucleus, with a polar filament coiled 5–6 times at the posterior end and terminating at an anchoring disk at the anterior end (Fig. 5B–D). The posterior vacuole was occasionally visible within mature spores. The wall of the spore was composed of a cell membrane within an electron-lucent endospore (10 nm) and an electron- dense exospore (2 nm).