Retipenna sichuanica Yang & Yang 1992

[54] Retipenna sichuanica Yang & Yang, 1992 (Figs 64, 88) Retipenna sichuanica Yang & Yang, 1992: 464. Type locality: China (Sichuan, Luding, Xinxing). Holotype in CAU. Diagnosis. This species is characterized by the presence of the relatively large body, the head, thorax and wings without markings, and the median arch of male gonarcus with deep U-shaped invagination. Description. Male. Body length 13.5 mm, forewing length 22.0 mm, hindwing length 18.5 mm. Head without spots, vertex raised. Compound eyes prominent and black. Antennae yellow, scape and pedicel wider than flagellum. Frons, clypeus and gena not marked. Maxillary and labial palpi brownish yellow. Pronotum anterior margin shorter than posterior margin, meso- and metanotum without markings. Legs with dense setae, without spots. Pretarsal claws brown, with basal dilation. Forewing broad, without shadings. Pterostigma indistinct. Costal area with 30 crossveins; 16 radial crossveins present. m1 smaller than m2; im ovoid; 12 psm-psc crossveins present. c1 smaller than c2, dcc closed. A1 forked, A2 and A3 simple. Inner gradate series with 11 crossveins, outer gradate series with 12 crossveins. Hindwing broad, without shadings. Costal area with 25 crossveins; 17 radial crossveins and 10 psm-psc crossveins present. Inner gradate series with 10 crossveins, outer gradate series with 11 crossveins. Abdomen with dense setae. Tergum VII and sternum VII subquadrate in lateral view; tergum VIII slightly shorter than tergum VII; sternum VIII fused with sternum IX and with small tubercle near tip; tergum IX fused with ectoproct. Callus cerci ovoid. Gonarcus arcuate, median arch with deep U-shaped invagination, lateral arms narrow at base and wide at tip, entoprocessus widest at tip; arcessus widest near base. Material. Holotype ♂, China, Sichuan, Luding, Xinxing, 1800 m, 1983.VI.14, Shuyong Wang (CAU). Distribution. China (Sichuan). Remarks. This species has no spots or markings on body, but can be distinguished by the U-shaped invagination of median arch of male gonarcus and the broad arcessus.