Chelonarium signatum is known from northern and central South America. The original description of C. signatum was very brief and lacked description of much of the external morphology and the genitalia. We present a redescription of C. signatum based on examination of material from southern Paraguay, including descriptions of the male and female genitalia. Images are presented of the adult habitus and external morphology, along with notes on the reproductive biology and collection in Paraguay. The history of the type specimen is traced, and photographs of the specimen and its labels are provided. A lectotype is designated for the species.