Key for the Rio Grande do Sul species of Rhinocricus
1. Pairs of scobinae beginning in the sixth segment............................................................. 2
- Pairs of scobinae beginning from seventh or eighth segment.................................................... 3
2. Anterior gonopods sternite as long as coxite or telepodite....................................... R. serranus sp. nov.
- Anterior gonopods sternite shorter than coxite or telepodite.................................................... 4
3. Scobinae beginning in the seventh segment................................................................. 5
- Scobinae beginning in the eighth segment.................................................................. 6
4. Posterior gonopod tibiotarsus with broad distal lamella.......................................... R. serratus Attems
- Posterior gonopod tibiotarsus with narrow distal lamella forming a more or less bifurcated distal end...................................................................................................... R. divaricatus Schubart
5. Anterior gonopod sternite wider than long................................................... R. gauchus sp. nov.
- Anterior gonopod sternite longer than wide.................................................. R. guaritas sp. nov.
6. Anterior gonopod sternite as long as wide, almost reaching the distal apex of coxite; basal width of sternite almost double the width of each coxite.................................................................. R. padbergi (Verhoeff)
- Anterior gonopod sternite small and short, around 2/3 of coxite length............................................ 7
7. Anterior gonopod sternite longer than wide, distal end with small groove and transversal semicircular depression; posterior gonopod tibiotarsus with indented lamella...................................................... R. itauba sp. nov.
- Anterior gonopod sternite as long as wide, distal end only with small groove; posterior gonopod tibiotarsus with smooth lamella................................................................................... R. vacariensis sp. nov.