A study of type material of several longidorid species revealed misinterpretations of the amphid structure with respect to shape of the amphidial fovea and amphidial aperture. A standardised terminology of the amphid structure within the Longidoridae is proposed. Former and recent hypotheses on phylogenetic relationships within the family based, respectively, on morphological and on molecular data are discussed, as well as possible implications for the systematics of the family Longidoridae. As a result of this study the following new combinations are proposed: Longidorus boshi n. comb. (syn. Paralongidorus boshi); Longidorus monegrensis n. comb. (syn. P. monegrensis); Longidorus spiralis n. comb. (syn. P. spiralis) and Longidorus cedari n. comb. (syn. Longidoroides cedari). Additional information is provided for Longidoroides bikanerensis, Paralongidorus buchae and P. zenobiae. © 2007 Brill Academic Publishers.