In 1912, MILLER united all the West European bats with very long ears joined across the forehead and with 36 teeth into one species, Plecotus auritus (LINNAEUS, 1758). By doing so he followed BLASIUS (1857), DOBSON (1878) and TROUESSART (1910). This situation, one species without subspecies, remained till 1940. In that year V. & E. MARTINO described a subspecies of the Long-eared Bat, Plecotus auritus meridionalis, based on animals from Slovenia, Yugoslavia. The animals were characterized by having larger skulls than the bats in Northern Europe. In 1957, BAUER studied a collection of bats from Spain. He described a new subspecies, Plecotus auritus hispanicus, on bats from the surroundings of Linares de Riofrio, Salamanca. The bullae auditori of the Spanish animals were smaller than those of animals from Austria. The bats from Salamanca were more yellow-brown-coloured than the animals from Austria; the latter were grey-coloured with a brownish hue. From the description of BAUER (1957) it is clear that the author came across a taxonomic problem he could not explain at that time.