Key to the soldiers of Cyrilliotermes

1. Nasus broadly conical (Fig. 5 A–B)................................................... C. crassinasus, new species

- Nasus subcylindrical (Figs. 2A–D, 3A–B, 8A–B, E)......................................................... 2

2. Right mandible with cutting edge between A and M1 much longer than the distance between M1 and M2; (Fig. 9 A–B); nasus conspicuously upturned (Fig. 2A); sides of head capsule usually angular.............................. C. angulariceps

- Right mandible with cutting edge between A and M1 shorter than the distance between M1 and M2 (Figs. 9 C–F); nasus oriented anteriorly or moderately upturned; sides of head capsule not angular............................................. 3

3. Cutting edge between A and M1 short and concave (Fig. 9 E–F); apical teeth often rounded; head capsule elongate, usually with nearly straight lateral sides in dorsal view (Fig. 8 B); nasus not upturned............................... C. strictinasus

- Cutting edge between A and M1 long and straight (Fig. 9 C); apical teeth with sharp points; head capsule not elongate (Fig. 3 B); nasus slightly upturned............................................................. C. brevidens, new species