Van Heurck -- Synopsis des Diatomées de Belgique -- Index
| Pterotheca | aculeifera Grunow = Pyxilla ?? aculeifera Grunow | Page -- | Plate 83 | Figure13,14 | Note 198 |
| Pterotheca | aculeifera var. [Grunow] = Pyxilla ?? aculeifera var. Grunow | Page -- | Plate 83bis | Figure 5 | |
| Pterotheca ? | danica Grunow = Stephanogonia danica Grunow | Page -- | Plate 83bis | Figure 7,8 | |
| Pterotheca | dubia Grunow = Pyxilla ? dubia Grunow | Page -- | Plate 83 | Figure 7,8 | |
| Pterotheca | dubia var. [Grunow] = Pyxilla dubia var. [Grunow] | Page -- | Plate 83bis | Figure 12 | |
| Pterotheca | kittoniana Grunow = Pyxilla ?? kittoniana Grunow | Page -- | Plate 83 | Figure 10,11 | |
| Pterotheca | kittoniana Grunow = Pyxilla ?? kittoniana Grunow | Page -- | Plate 83bis | Figure 9,10,11 | |
| Pterotheca | subulata Grunow = Pyxilla ?? subulata Grunow | Page -- | Plate 83bis | Figure6 |