| Name | Nitzschia sigmatella W. Gregory |
| Authorship | W. Gregory |
| Rank | Species |
| Placed in | Nitzschia Hassall |
| Holdings | 1 Specimen held in the Harvard University Herbaria identified as Nitzschia sigmatella W. Gregory |
| Identification made in | [no date] (1) |
| Name | Nitzschia sigmatella W. Gregory |
| Authorship | W. Gregory |
| Rank | Species |
| Placed in | Nitzschia Hassall |
| Holdings | 1 Specimen held in the Harvard University Herbaria identified as Nitzschia sigmatella W. Gregory |
| Identification made in | [no date] (1) |