The first redescription of T. radiata Selenka, 1879 based on study of a live population and material other than the type is presented. A neotype is proposed for the species, from a locality some 400 km to the southwest as it has not been found in its original type locality, Guanabara Bay (Rio de Janeiro, Rio de Janeiro State).
Brazil; Guanabara Bay; São Sebastião Channel; taxonomy