Megarthrus affinis Stephens, 1834 (nomen dubium, see note below)
Megarthrus affinis Miller, 1852 (nec Stephens, 1834; junior primary homonym)
Megarthrus bellevoyei Saulcy, 1862


In works before the genus revision by Cuccodoro and Löbl (1997) this species is usually listed as Megarthrus affinis Miller, 1852, but this name is a junior primary homonym and therefore invalid. The older primary homonym Megarthrus affinis Stephens, 1834 is a nomen dubium that cannot be identified from its description and the type material is lost (Cuccodoro and Löbl 1997). It may actually refer to the present species as well, but Cuccodoro and Löbl (1997) prefer to resurrect the younger synonym bellevoyei, and I follow this notion here.