Ctenoplectron solomonis sp. nov. from Guadalcanal, the first representative of Melandryidae Leach, 1815 from the Solomon Archipelago, is described and illustrated. Callidircaea Champion, 1916 stat. restit. is removed from synonymy with Megapselaphus Gemminger in Gemminger & Harold, 1870. Two new combinations are proposed: Ctenoplectron venustus (Champion, 1895) comb. nov. and C. lignivorus (Lea, 1896) comb. nov. (both from Callidircaea). Taxonomy and morphological features of Callidircaea, Ctenoplectron Redtenbacher, 1868, and Megapselaphus are discussed. Megapselaphus is hypothesized to be a senior synonym of Ctenoplectron. Callidircaea sexnotata, the type species of its genus, is illustrated for the first time.