Toxorhina (Ceratocheilus) alexanderi n.sp. (Diptera: Tipulidae) is described, and a redescription of the type specimen of the related T. (C.) cornigera (Speiser, 1907) is given. The characteristics of the subgenus Ceratocheilus are discussed and the peculiar structure corniculus is figured and compared with the corresponding organ in Trichoneura (Ceralolimnobia) munroi Alexander, 1920, of the tribe Lechriini. The abdominal terminalia of the female of T. (C.) munroi have also been studied and similarities with those of T. (C.) alexanderi n.sp. are pointed out.