(Haeckel)
Three concentric latticed shells; pores on outermost relatively small, circular, regularly arranged, without frames (in some specimens frames around the pores can develop, in which case this species merges with Actinomma sol). Cortical shell usually smooth, barren of spines. Cortical shell diameter: ca. 80 µm.
Ref.: Boltovskoy and Riedel (1980).