Abstract
A new platycephalid, Grammoplites knappi, is described from specimens from the South China Sea (off Sarawak, Borneo Island, the Gulf of Thailand and Hainan Island, China). The species is distinguished from other species of Grammoplites by the following combination of characters: 5 or fewer gill rakers on the lower arch, narrow interorbit, large eye diameter, short uppermost preopercular spine, no papillae on lips, small body scales and pored lateral line scales with posteriorly-positioned ctenii and a single exterior opening on the posterior margin. A key to the five species of Grammoplites is presented.
