Type species: Helopora tenuis James, 1878
This genus includes the species:
| Arthrostylus conjunctus | Ulrich, 1890 | U. Ordovician | USA (Minnesota) |
| Arthrostylus obliquus | Ulrich, 1890 | U. Ordovician | USA, Greenland |
| Arthrostylus curtus | (Ulrich, 1882) | U. Ordovician | USA (Kentucky) |
| Arthrostylus pentagonus | Grubbs, 1939 | Silurian | USA |
| Arthrostylus tenuis | (James, 1878) | Ordovician | USA |
|
|
|
|