Larval agonistic displays are reported from three sympatric synlestid damselflies: Episynlestes cristatus , Synlestes tropicus and Chorismagrion risi . There were strong similarities between the species in the observed displays. Repertoires of all three species contained elements otherwise known only from larval Lestidae (conventionally interpreted as a member of the sister group to the Synlestidae). In night-time observations under infrared illumination different displays, some similar to those of coenagrionids, occurred. On the basis of similarities in larval displays I conclude that Chorismagrion risi , regarded on adult characters as an enigmatic form, is a member of the Synlestidae and that the Synlestidae and Lestidae are closely allied.