68 Diodorus Siculus, i. 27. 4; Plutarch, _Isis et Osiris_, 21, 22, 38, 61; Porphyry, _De antro nympharum_, 24; Scholiast on Apollonius Rhodius, ii. 517; Canopic decree, lines 36 _sq._, in W. Dittenberger’s _Orientis Graeci Inscriptiones Selectae_, vol. i. p. 102, No. 56 (lines 28 _sq._ in Ch. Michel’s _Recueil d’Inscriptions Grecques_, p. 417, No. 551); R. V. Lanzone, _Dizionario di Mitologia Egizia_, pp. 825 _sq._ On the ceiling of the Memnonium at Thebes the heliacal rising of Sirius is represented under the form and name of Isis (Sir J. G. Wilkinson, _Manners and Customs of the Ancient Egyptians_, London, 1878, iii. 102). 69 Porphyry and the Canopic decree, _ll.cc._; Censorinus, _De die natali_, xviii. 10, xxi. 10. In inscriptions on the temple at Syene, the modern Assuan, Isis is called “the mistress of the beginning of the year,” the goddess “who revolves about the world, near to the constellation of Orion, who rises in the eastern sky and passes to the west perpetually” (R. V. Lanzone, _op. cit._ p. 826). According to some, the festival of the rising of Sirius and the beginning of the sacred year was held on the nineteenth, not the twentieth of July. See Ed. Meyer, “Ägyptische Chronologie,” _Abhandlungen der königl. Preuss. Akademie der Wissenschaften_, 1904, pp. 22 _sqq._; _id._, “Nachträge zur ägyptischen Chronologie,” _Abhandlungen der königl. Preuss. Akademie der Wissenschaften_, 1907, pp. 7 _sqq._; _id._, _Geschichte des Altertums_,2 i. 2. pp. 28 _sqq._, 98 _sqq._ _ 70 Eudoxi ars astronomica, qualis in charta Aegyptiaca superest_, ed. F. Blass (Kiliae, 1887), p. 14, οἱ δὲ ἀσ[τρο]λ[ό]γοι καὶ οἱ ἱερογραμμ[ατεῖς] χ[ρῶν]ται ταῖς κατὰ σελή[ν]ἠ[ν] ἡμ[έ]ραις καὶ ἄγουσι πανδημ[ι]κὰς ἕ[ορ]τας τινὰς μὲν ὡς ἐνομί[σθ]ἠ τὰ δὲ καταχυτήρια καὶ κυνὸς ἀνατολὴν καὶ σεληναῖα κατὰ θεό[ν], ἀναλεγόμενοι τὰς ἡμέρας ἐκ τῶν Αἰγυπτίων. This statement of Eudoxus or of one of his pupils is important, since it definitely proves that, besides the shifting festivals of the shifting official year, the Egyptians celebrated other festivals, which were dated by direct observation of natural phenomena, namely, the annual inundation, the rise of Sirius, and the phases of the moon. The same distinction of the fixed from the movable festivals is indicated in one of the Hibeh papyri, but the passage is unfortunately mutilated. See _The Hibeh Papyri_, part i., edited by B. P. Grenfell and A. S. Hunt (London, 1906), pp. 145, 151 (pointed out to me by my friend Mr. W. Wyse). The annual festival in honour of Ptolemy and Berenice was fixed on the day of the rising of Sirius. See the Canopic decree, in W. Dittenberger’s _Orientis Graeci Inscriptiones Selectae_, No. 56 (vol. i. pp. 102 _sq._).