Genus
Calathium Billings, 1865
Classification
| Organism group | Biota | 
| Incertae sedis (fossils) | |
| Phylum | Receptaculita | 
| Order | Receptaculitales | 
| Family | Receptaculitaceae | 
| Genus | Calathium | 
| Species | formosum | 
| Genus | Fisherites | 
| Ischadites | |
| Receptaculites | 
| Organism group | Biota | 
| Incertae sedis (fossils) | |
| Phylum | Receptaculita | 
| Order | Receptaculitales | 
| Family | Receptaculitaceae | 
| Genus | Calathium | 
| Species | formosum | 
| Genus | Fisherites | 
| Ischadites | |
| Receptaculites |