Inscribed tablets. Objects, generally of soft stone, usually shale or sandstone, containing various lines and formal characters incised or in relief. Some of them are undoubtedly prehistoric and susceptible of interpretation in the light of aboriginal ornamentation and symbolism ; others are forgeries. While it would perhaps be too much to say that there exists N. of Mexico no tablet or other ancient article that contains other than a pictorial or pictographic record, it is safe to assert that no authentic specimen has yet been brought to public notice. Any object claimed to be of pre-Columbian age and showing hieroglyphic or other characters that denote a degree of culture higher than that of the known tribes, is to be viewed with suspicion and all the circumstances connected with its discovery subjected to rigid scrutiny. The same remarks apply to engraved copper plates. In the latter material, the uneven surface produced by natural corrosion is often mistaken for attempts at inscriptions. See Grave Creek mound, Pictography.