Biconvex spongy disc more or less clearly partitioned into chambers by circular or spiral, continuous or broken, and radial bands. Both surfaces covered by a thin porous sieve plate which can extend beyond the central spongy mass (spongy shell 3). With or without protruding spines. Very similar morphotypes with an oval outline and a pylome have been cited under the name Stylochlamydium venustum Bailey (Stylochlamydium asteriscus, right picture). Diameter of disc: 150-350 µm.
Ref.: Boltovskoy and Vrba (1988).