| Fortiborus anisopterae, side, length: 5.2 mm. |
| Fortiborus anisopterae, top, length: 5.2 mm. |
| Fortiborus indigens, antennal club. |
| Fortiborus indigens, declivity. |
| Fortiborus indigens, holotype, length: 7.0 mm. |
| Fortiborus indigens, holotype top, length: 7.0 mm. |
| Fortiborus major, homotype, length: 5.5 mm. |
| Fortiborus major, homotype top, length: 5.5 mm. |
| Fortiborus major, junior synonym Xyleborus siclus holotype, length: 5.5 mm. |
| Fortiborus major, junior synonym Xyleborus siclus holotype antennal club front face. |
| Fortiborus major, junior synonym Xyleborus siclus holotype antennal club rear face. |
| Fortiborus major, junior synonym Xyleborus siclus holotype side, length: 5.5 mm. |
| Fortiborus pilifer, antenna, length: 6.0-6.3 mm. |
| Fortiborus pilifer, holotype, length: 6.0-6.3 mm. |
| Fortiborus pilifer, holotype top, length: 6.0-6.3 mm. |
| Fortiborus pilifer, pronotum. |
| Fortiborus sulcinoides, length: 6.0-7.0 mm. |
| Fortiborus sulcinoides, top, length: 6.0-7.0 mm. |