Morphological comparative study of four new species of the genus Aulolaimus de Man, 1880 (Nematoda, Aulolaimidae) from the Iberian Peninsula

Four new species of the genus Aulolaimus are described from natural and semi-natural habitats of southern Iberian Peninsula: Aulolaimuscribatus sp. n., Aulolaimus. distortus sp. n., Aulolaimuslabiostellatus sp. n. and Aulolaimusquercophilus sp. n. They are studied with light- and scanning electron microscopy. Several morphological features are especially useful to characterize the new species and to distinguish them from their relatives: labial disc, cuticle sculpturing (number of longitudinal ridges, shape and arrangement of punctations, etc.), ventrosublateral and median pieces of the vagina, female tail and, male secondary sexual characters.