n.protozoa with spherical bodies and stiff radiating pseudopods
英汉双解大词典
heliozoan/ˌhiːlɪəʊˈzəʊən/
1.
N（名词）
any protozoan of the mostly freshwater group Heliozoa, typically having a siliceous shell and stiff radiating cytoplasmic projections: phylum Actinopoda (actinopods) 任一一种淡水太阳虫目原生动物