Left lateral (a) and dorsal (b) views of the endophallus and ventral view of the aedeagal apex (c) of Trephionus spp.: 10 T. kinoshitai from Mt. Shirouma 11 another specimen of T. kinoshitai from Mt. Shirouma, showing directions and examples of measurements for descriptions 12 T. cylindriphallus sp. n., holotype male; 13 T. cylindriphallus sp. n., a paratype male from Abe Pass 14 T. niumontanus sp. n., holotype male 15 T. babai from Mt. Ishikiri; 16 T. shibataianus from Mt. Naka 17 T. inexpectatus sp. n., holotype male 18 T. abiba sp. n., holotype male 19 T. bifidilobatus sp. n., holotype male. Abbreviations: AW, the width of the aedeagus at the ostium from the dorsal view; BD, the basal diameter of the lobe from dorsal view; da, dorsoapical lobe; db, dorsobasal lobe; go, gonopore; lb, left laterobasal lobe; rb, right laterobasal lobe; sl, sclerotized lobe.