Figures 37–39, 60

Ecnomina scindens Neboiss, 1982: 295, figs 44, 45, 50–53. — Neboiss 1986: 155.

Diagnosis. Daternomina scindens resembles D. merga in having relatively long superior and inferior appendages, but differs in having more robust appendages.

Description. (Revised after Neboiss 1982). Head, body and wings brown; wings (Neboiss 1982, fig. 50; Neboiss 1986: 155) similar to D. irrorata (Fig. 1). Forewing length about 3.3 times width: male 4.6–5.0 mm, female 4.5 mm. Forewing fork 2 relatively long, sessile, about 1.6–1.8 times length of fork 3, nygma present; fork 3 about 1.9–2.0 times length footstalk, footstalk length about 2.0–2.5 times length cross-vein m; r-m and m displaced at fork 3 by about 1.2–1.7 times length cross-vein m; fork 4 shorter than fork 3; fork 5 long, about 1.5 times length of fork 4. Hindwing length about 3 times width; fork 2 sessile, length about 1.5–1.8 times length of fork 3.

Male. Tergum X membranous with a pair of lobes (Fig. 39). Superior appendages long, laterally compressed; in lateral view robust, sub-rectangular, length about 2.5 times width (Fig. 37); in dorsal view, relatively slender, length about 5 times width, with two rows of spines on inner surface (Fig. 39). Phallus simple, tube-like, with a pair of robust, hook-like processes dorso-laterally; with a single, slender, elongate, curved sword-like process (phallic guide) arising from near the base of the inferior appendages (Fig. 37). Inferior appendages long, dorso-ventrally flattened; in ventral view fused basally to form a single plate, distal twothirds separated narrowly by a deep mesal split, with pair of digitiform apices (Fig. 38); in lateral view robust, length about 2.5 times width, narrowed at distal third (Fig. 37).

Female. Genitalia with a pair of large relatively narrowly separated ‘tongue-shaped’ lobes on sternite VIII (Fig. 60).

Material examined: Western Australia. Holotype male, Harvey River near Harvey Falls, 15 km E of Harvey, 21 Nov 1978, A.N. (NMV, T- 6332). Paratypes, 5 males (specimen PT-626 figured), 25 females (specimen PT-724 figured), collected with holotype (NMV). Other material. 1 male, 4 females, Harvey R., below Harvey Falls, 15 Nov 1980, A. Wells and M. Brock; 1 female, 24 km NW of Walpole, 15 Nov 1958, E.F. Riek (ANIC); 1 male, Frankland R., circular pool, 6 km NE of Walpole, 27, Nov 1978, A.N.; 3 males, 1 female, Beedelup Falls, 16 km W of Pemberton, 13 Nov 1958, E.F. Riek (ANIC); 1 male, Augustus R., Collie, 30 Oct 1983, S. Bunn.

Remarks. Daternomina scindens is recorded from five sites in south-western Australia (latitudinal range 32°46' - 34°57'S). Neboiss’s (1982) figures have been redrawn to allow direct comparisons and to accompany the description that is revised in light of new interpretations of Daternomina genitalic structures.