Van Heurck -- Synopsis des Diatomées de Belgique -- Index
| Zygoceros | circinus Bail. | Page -- | Plate 105 | Figure 13 | |
| Zygoceros | mobiliensis Bailey = Biddulphia baileyi W. Sm. | Page 205 | Plate 101 | Figure 4,5,6 | |
| Zygoceros ? | quadricornis Grunow | Page -- | Plate 105 | Figure 5,6,7 | |
| Zygoceros | rhombus Ehrenb. = Biddulphia rhombus (Ehrenb.) W.Sm. | Page -- | Plate 99 | Figure 1,3 | |
| Zygoceros | tuomeyi Bailey = Biddulphia tuomeyi (Bailey) Roper | Page -- | Plate 98 | Figure 2,3 |