Among the vertebrate remains discovered by M. Houzeau de Lehaie in the “Craie brune phosphatée” of Ciply, is the crown of a large tritoral tooth, of unusual form and somewhat difficult of determination. A study of the reptilian teeth from the New Jersey Greensand in the Philadelphia Academy of Sciences has, however, suggested to the writer a plausible explanation of the specimen; and a brief notice of its characters may perhaps lead to the discovery of more satisfactory evidence of the animal to which it pertains.