This paper deals with the morphology and life history of two new species of septate greganines (Apicomplexa: Conoidasida: Gregarinidae) of the genus Unilobus Théodoridès, Desportes & Jolivet, 1984, obtained from two tenebrionid beetles of West Bengal, India.These are Unilobus gonocephali n. sp. from Gonocephalum sp. (Insecta: Coleoptera: Tenebrionidae) and Unilobus scleroni n. sp. from Scleron irregulate (Insecta: Coleoptera: Tenebrionidae). Total length of U. gonocephali varies from 200–467 μm. Gametocysts spherical, 410 μm in average diameter, dehisces through 7–9 sporoducts. U. scleroni is comparatively smaller, total length varies from 61–232 μm. Gametocyst spherical with average diameter 350 μm, dehices through 10 to 12 sporoducts. The two new species share traits which define the genus such as the absence of epimerite, expanded protomerite and late association. These two described species are not only different from the previously described species, but also oocysts (= spores) entirely different from each other in characters like measurements, number of sporoduct and in host range. This communication also confi rmed the validity of the genus Unilobus Théodoridès, Desportes & Jolivet, 1984 and its placement under the family Gregarinidae Labbé, 1899.