Nephax Pearman, 1935: 134. Type species (by original designation): Nephax sofadanus Pearman, 1935: 134.

REVISED DIAGNOSIS: Belonging to Amphientomidae. Forewings densely covered with scales. Median ocellus absent (even in fully-winged forms); lateral ocelli widely separated, close to compound eyes. Antenna with 13 articles (i. e. 11 flagellomeres). P2 with spur sensillum on inner side and some external macrochaetae in addition to the simple and relatively short general pilosity (Fig. 6g). Mandibles with shortened apical part (Fig. 6h). Labrum lacking pair of parallel longitudinal labral rods; weakly developed sclerites originating from labral nodes diverging and running almost parallel to antero-lateral margin of labrum (Fig. 6f). Phallosome V-shaped, lacking internal sclerotizations. Internal T-shaped sclerite of female subgenital plate welldeveloped (Fig. 6e). Nymphs with simple straight hairs on dorsal side of thorax and abdomen.

SPECIES ASSIGNED TO NEPHAX: Nephax sofadanus Pearman, 1935; Nephax capensis Pearman, 1935; Nephax postalatus Lienhard, 2009.

DISCUSSION: The genus Nephax is well-defined by the autapomorphic shortening of the mandibles, which has been observed in the type species and in N. postalatus. The South African Nephax capensis Pearman probably does not belong to this genus, as it is defined here; the species has two ocelli placed close together and mandibles of normal shape (see Pearman, 1935). However, we provisionally retain the original combination, because no assignment to another amphientomid genus is evident at present. The species Seopsis nepalensis New, 1973, has been tentativley transferred to Nephax by Li Fasheng (1993) (see also Lienhard & Smithers, 2002). Based on the original description by New (1973) it is clear that this species does not belong to this genus as it is defined here (ocelli close together, phallosome with internal sclerites, spermapore plate large and associated with gonapophyses; see New, 1973: figs 5 and 7). Thus the original combination Seopsis nepalensis New comb. rev. is here reinstated.

The striking differences in forewing venation between the macropterous species N. postalatus and the brachypterous species N. sofadanus are probably related to wing reduction; exactly the same differences have been observed in the genus Marcenendius, between the macropterours M. nostras and the brachypterous M. fortunatus. In macropterous forms Rs is connected to M by a short crossvein and the stigmapophysis is situated distally of the R1-Rs bifurcation (this corresponds to the typical venation of Amphientomidae; see Smithers, 1972); in brachypterous forms Rs and M are fused for a length and the stigmapophysis is situated on R stem, basally of the R1-Rs bifurcation. We consider the striking similarity in forewing venation between these brachypterous forms not as a synapomorphy but as a case of convergence due to wing reduction.