Key to the genera within Thorectinae (amended from Cook & Bergquist, 2002)
1. Sponge dermis armoured............................................................................... 2
- Sponge dermis unarmoured............................................................................. 8
2. Sponge dermis heavily armoured......................................................................... 3
- Sponge dermis armouring partial with a striated pattern...................................... Skolosachlys gen.nov.
- Sponge dermis armouring superficial..................................................................... 6
3. Skeleton regular...................................................................................... 4
- Skeleton irregular..................................................................................... 5
4. Primary fibres large diameter..................................................................... Thorecta
- Primary fibres similar to secondary fibres........................................................ Thorectandra
5. Primary fibres fasciculating.......................................................... Rubrafasciculus gen.nov.
- Primary fibres not fasciculating................................................................ .. Aplysinopsis
6. Primary fibres fasciculating............................................................................. 7
- Primary fibres not fasciculating............................................................. .. Petrosaspongia
7. Heavy collagenous matrix................................................................. Fascaplysinopsis
- Thin walled lamello-digitate or foliose sponges, fibres parallel to the surface............................ Collospongia
8. Quarternary fibers present.............................................................................. 9
- Quartenary fibres absent............................................................................... 10
9. Fenestrate surface, fasciculating primary fibres.................................................. Fenestraspongia
- Conulose surface, primary fibres mostly non-fasciculate............................................... Luffariella
10. Primary and secondary fibres uncored.................................................................... 11
- Primary and secondary fibres cored.......................................................................12
11. Axially concentrated skeleton................................................................... Thorectaxia
- Dense branching, non-hierarchical fibre network................................................ Dactylospongia
12. Secondary fibres cored............................................................................ Hyrtios
- Secondary fibres uncored.............................................................................. 13
13. Primary fibres strongly fasciculated throughout sponge............................................ Fasciospongia
- Primary fibres not strongly fasciculated throughout sponge................................................... 14
14. Upright growth form, on a basal stalk, smooth surface.................................................. Taonura
- Low growth forms................................................................................... 15
15. Secondary fibre skeleton well developed................................................................... 6
- Skeleton comprises primary and secondary fibres in equal portions 17
16. Honeycomb pattern at surface, colour darkens upon collection....................................... Smenospongia
- Without honeycomb pattern at surface, colour does not change........................................ Cacospongia
17 Heavy collagenous mesohyl, irregular skeleton................................................... Semitaspongia
- Low to moderate mesohyl collagen, regular skeleton.............................................. Scalarispongia