53. BORYSTHENIO ... AMNE = Bory̅sthĕnē. The river is the modern Dnepr, which flows into the Black Sea about 120 kilometres east of Odessa, about 50 kilometres east of the mouth of the Bug (Hypanis). For the metrical device here employed, compare Prop II vii 17-18 'hinc etenim tantum meruit mea gloria nomen, / gloria ad hibernos lata Borysthenidas', Avienus Descr Orb 448 'inde Borysthenii uis sese fluminis effert' & 721 'ora Borysthenii qua fluminis in mare uergunt'.
53. LIQVIDISSIMVS is not found elsewhere in Ovid.
53. DIRAPSES. The river is not mentioned elsewhere.
54. MELANTHVS. The modern Melet Irmak flows into the Black Sea about 25 kilometres west of Trabzon (Trapezus). It is mentioned in passing at Pliny NH VI 11.
55-56. QVIQVE DVAS TERRAS, ASIAM CADMIQVE SOROREM, / SEPARAT ET CVRSVS INTER VTRAMQVE FACIT. The Tanais (Don) is named as the border between Europe and Asia by Pliny (NH IV 78) and Avienus (Descr Orb 28 & 861). Compare as well Lucan III 272-76 'qua uertice lapsus / Riphaeo Tanais diuersi nomina mundi / imposuit ripis Asiaeque et terminus idem / Europae, mediae dirimens confinia terrae, / nunc hunc, nunc illum, qua flectitur, ampliat orbem'.
Vibius Sequester (Geog Lat min [Riese] p. 212) has an entry 'Hypanis Scythiae qui, ut ait Gallus "uno tellures diuidit amne duas": Asiam enim ab Europa separat'. The Hypanis cannot be the river Ovid is here referring to, for it has already been mentioned in 47; but, as Lenz saw, the line from Gallus could well have been in Ovid's mind as he wrote this passage. Professor R. J. Tarrant notes that the extraordinary Cadmique sororem could well be a borrowing from the earlier poet.
57-58. INTER MAXIMVS OMNES / CEDERE DANVVIVS SE TIBI, NILE, NEGAT. A similar conjunction at Tr III x 27-28 'ipse, papyrifero qui non angustior amne, / miscetur uasto multa per ora freto'. Herodotus compares the courses of the Nile and the Danube, concluding 'οὕτω τὸν Νεῖλον δοκέω διὰ πάσης τῆς Λιβύης διεξιόντα ἐξισοῦσθαι τῷ Ἴστρῳ' (II 34), referring to the length of the rivers, however, rather than their volume of discharge. At NQ III 22 Seneca mentions the belief of some that because of their large size and the fact that their sources were both unknown the Nile and the Danube must both have been formed at the creation of the world, unlike other rivers. At IV 1 1-2 he argues against those who equated the two rivers, pointing out that the source of the Danube was known to be in Germany, and that the two rivers flood at different times of the year.
59. COPIA TOT LATICVM QVAS AVGET ADVLTERAT AQVAS. The comparative freshness of the waters of the Black Sea was well known in antiquity. Besides the passages cited at 37-38, see Polybius IV 42 3 and Philostratus Imag I 13 7.
61-62. QVIN ETIAM, STAGNO SIMILIS PIGRAEQVE PALVDI, / CAERVLEVS VIX EST DILVITVRQVE COLOR. Ovid's drinking water was, on the other hand, rather brackish: 'est in aqua dulci non inuidiosa uoluptas: / aequoreo bibitur cum sale mixta palus' (EP II vii 73-74).
63. INNATAT VNDA FRETO DVLCIS. Similar wording at Macrobius Sat VII 12 32 'superficies maris, cui dulces aquae innatant, congelascit'.