Description of Tachygonetria combesi n. sp. and redescriptions of four species of Tachygonetria Wedl, 1862 (Nematoda: Pharyngodonidae), with a new diagnosis of the genus.

The generic diagnosis of Tachygonetria Wedl, 1862 is modified based on the study and redescription of Tachygonetria vivipara Wedl, 1862 (collected from large intestine of Uromastyx acanthinurus Bell, from North Africa) and T. dentata (Drasche, 1883) (collected from large intestine of Testudo graeca Linnaeus in Settat, Morocco and T. hermanni Gmelin in Catalonia, Spain). The following taxa were redescribed: Tachygonetria conica (Drasche, 1883) and T. robusta (Drasche, 1883) (both from the large intestine of Testudo graeca collected in Settat, Morocco); the subspecies Tachygonetria conica nicollei (Seurat, 1918) is suppressed. A new species, T. combesi n. sp. is described from the large intestine of Testudo hermanni, which confirms the revision of the genus. Scanning electron microscopical studies revealed substantial interspecific differences in the structure of the caudal end.