Cosmocerca parva Travassos 1925 (Asca-ridida, Cosmocercoidea, Cosmocercidae) was originally described from Helosia nasus (Leptodactylidae) of Angra dos Reis, State of Rio de Janeiro, Brazil. It has also been reported in Leptodactylus chaquensis, L. elenae, Hyla fuscovaria and Bufo paracnemis from Paraguay.