Inscription of Olympus to his grandfather

[This inscription from the Mitreo di Piazza S. Silvestro in Capite] has been preserved and stands on the back of a marble slab (H. 0.54 Br. 2.25). It was found in 1867 and is divided by small columns into four square and three semicircular niches, in which the seven planets must have been represented (Rome, Museo Naz. Terme, Inv. No. 662). The sanctuary was in use between 357-382 A.D.).MMM II 196 No.9; Helbig, Fuhrer, II, 71 No. 1274; Paribeni, Terme Diocl., 139 No. 282; Vermaseren, Mithrasdienst Rome, 79.Saxum marmoreum longum 2.25, largum 0.54 effossum mense septembri anni 1867... ad viculum S. Silvestri…