| Type | PARATYPES |
| Catalogue # | OSUM 19784 |
| Type locality | Powell River about 2 mi. upstream from Dryden, on a rocky shoal in fairly rapid water about ankle deep, about 4 mi. downstream from C.C. Adam's Lot 45, [Lee C.], Virginia |
| Collector(s) | C.C. Adams |
| Date collected | 3 Sept. 1899 |
| # Specimens | 47 dry |
| Description | Memoirs of the National Academy of Science 12(2): 11 |
| Remarks | |
| Current status | Io fluvialis (Say, 1825) |
| Type | PARATYPES |
| Catalogue # | OSUM 19785 |
| Type locality | Powell River at Olinger, below the mill dam, on a shoal with numerous large boulders, [Lee C.], Virginia |
| Collector(s) | C.C. Adams |
| Date collected | 5 Sept. 1899 |
| # Specimens | 21 dry |
| Description | Memoirs of the National Academy of Science 12(2): 11 |
| Remarks | |
| Current status | Io fluvialis (Say, 1825) |