Male genitalia in lower (non-Ditrysian) Heteroneurans typically have a distinct 'capsule', comprising a well sclerotized vinculum plus tegumen, with usually distinct uncus and often a gnathos present. Valvae are often tightly joined by a transtilla and show in many families a row of special setae: the pectinifer, of which homology is uncertain. The sclerotised phallus tube or aedeagus has many associated sclerites of uncertain homology: carinal processes, juxta, anellar processes. In Nepticulidae the cornuti on the vesica are often elaborate. Other special cases discussed are the elaborate gnathos in some Opostegidae, probably replacing the aedeagus as intromittent organ, the thickening enclosing the opening of the ejaculatory duct in Nepticulidae, the juxta in Incurvarioidea and the peculiar aedeagus in Tischeriidae and the socii in Opostegidae and Tischeriidae. The female terminalia are, because of their Monotrysian nature, less complex than in Ditrysia. The ovipositor is piercing in the Incurvarioidea. The terminalia in Tischeriidae are complex, with more than the usual 2 pairs of apophyses. Other structures of interest are various vaginal sclerotisations (Nepticulidae), signa in the bursa and an accessory bursa in Nepticulidae.