Two new endemic genera of Ceratocanthinae are described from Madagascar. Cryptosphaeroides n. gen. includes C. hystrix (Paulian, 1991) n. comb., C. tenrec n. sp., C. hippocrepis n. sp. and C. ankaranensis n. sp. The genus seems to be restricted to the dry forests of North and West Madagascar. Pseudosynarmostes n. gen. includes P. mitsinjo n. sp. and P. perrieri (Fairmaire, 1898) n. comb. This genus is known from East and West Madagascar and shows a very unusual morphology which makes its position very isolated within all other known Ceratocanthinae.
Insecta, Coleoptera, Scarabaeoidea, Hybosoridae, sexual dimorphism, mouthparts, Nasutitermes nest, Madagascar, new genera, new species, new combinations.