O. B. Lower described, in 1911, the hesperiine skipper Telicota augias mesoptis Lower, 1911, but he neither stated the number of specimens before him nor designated a holotype. Our investigations indicate that Lower had at least 11 syntypes (7 males, 4 females), which are now registered in the Australian Museum, Sydney and South Australian Museum, Adelaide (SAMA). At least two authors (G. A. Waterhouse in 1933, and M. J. Parsons in 1998) attempted to resolve the taxonomy of mesoptis but neither of them made a valid lectotype designation in that the syntype they specified cannot be located and unambiguously identified to act as the unique type of the taxon. Thus, we designate a male specimen in SAMA (registration number: SAMA Database No. 31-001600) as the lectotype to become the unique bearer of the name mesoptis. This action does not affect the name or rank of the taxon, rather it constitutes a formal subsequent fixation since Lower’s name was introduced 110 years ago. With regard to nomenclature, the taxonomic status of mesoptis has changed several times, both in terms of rank and with the species or genus in which it has been combined. Currently, the correct nomenclature is Telicota paceka mesoptis Lower, 1911 and we recommend that this name be used to designate the Australian population rather than Telicota mesoptis mesoptis Lower, 1911 in which it has been known for the past 87 years (since 1934).