Genus
Calathium Billings, 1865
Luokittelu
| Organism group | Biota |
| Domain | Eukaryota |
| Kingdom | Plantae |
| Phylum | Chlorophyta |
| Subphylum | Chlorophytina |
| Class | Chlorophyceae |
| Order | Receptaculitales |
| Family | Receptaculitaceae |
| Genus | Calathium |
| Species | formosum |
| Genus | Fisherites |
| Receptaculites |