The article offers information on the species Oliarus beebei described by Z. P. Metcalf in 1945. Oliarus beebei was described from one male specimen and four female specimens. It was found that Oliarus beebei belonged to the genus Mnemosyne Stål, a supposition confirmed by a review of the original description. The figures of Oliarus beebei in Metcalf depict the species as having three carinae on the mesonotum.