A preliminary investigation of the genus Eucereon Hübner, [1819] has revealed that two of its species have been historically misidentified, one of them being its type species, E. archias (Stoll, 1790). The neotype designated by Travassos (1959) for this species is invalidated, and its original concept is reestablished based on the original description and illustrations. The original concept of Eucereon punctatum (Guérin-Méneville, [1844]) is also found to be different than that established in the literature. This discovery is based on a type specimen found at the Natural History Museum, London. Eucereon punctatum is the valid name of Theages quadricolor Walker, 1855, n. syn., E. quadricolor boreale Rothschild, 1912 n. syn., and E. quadricolor meridionale Rothschild, 1912 n. syn. The authors' concept of E. punctatum is hence-forth to be referred to by its oldest incorrect synonym, Eucereon mitigatum Walker rev. stat. Following the synonymic history for this species, this name here is considered to be the valid name for E. reticulatum Butler, 1877 n. syn., E. cribrum Möschler, 1877 n. syn., and E. ruficollis Lathy, 1899 n. syn. The true concepts of E. archias, E. punctatum, and E. mitigatum are redescribed, discussed and illustrated.