Key to species of Truttaedacnitis

1 Excretory pore situated at level of pseudobuccal capsule; oral collarette structures weak............................. 2

- Excretory pore situated behind nerve ring; oral collarette structures conspicuous.................................... 3

2 Spicules straight............................................................................ T. clitellarius

- Spicules bent.......................................................................... T. sphaerocephala

3 Dorsal cephalic ridge absent.................................................................... T. pybusae

- Dorsal cephalic ridge present...................................................................... T. truttae