Actinosphaerium arachnoideum Penard, 1904
Diagnosis: Body 50-90 µm. Ectoplasm with large vacuoles; endoplasm granulated with small vacuoles. Up to 12 nuclei, usually less than 6. Diameter of nucleus up to 12 µm. Nucleus with many small nucleoli. Axopodia long, up to four times the body diameter, anastomosing and sometimes smooth like filopodia.
Remarks: Dubious species.