Species
Holmograptus callotheca (Bulman, 1936)
Synonyymit
1932 Didymograptus callotheca — Bulman , pp. 16
Luokittelu
| Organism group | Biota |
| Kingdom | Animalia |
| Phylum | Hemichordata |
| Class | Pterobranchia |
| Subclass | Graptolithina |
| Suborder | Sinograptina |
| Order | Sinograptidae |
| Genus | Holmograptus |
| Species | callotheca |
| lentus | |
| spinosus |