[XXV.] Populonia: a town on the coast of Etruria. Ilva (the modern Elba): an island off the coast of Etruria near Populonia.
[XXVII.] Cinyras and Cupavo were sons of Cycnus. The legend tells us that Phaëthon rashly attempted to drive the chariot of the sun, and was killed by a thunderbolt from Jupiter, while so doing. Cycnus, who was devotedly attached to him, was changed into a swan while lamenting his death.
[XXVIII.] Mantua was Virgil's birthplace. Hence probably the insertion of this tradition as to its origin. Mincius, mentioned in the [next stanza,] is a Lombard river, the Mincio, and flows out from Lake Benacus (Lago di Garda).
[XXXVII.] Sirius, the dog-star, whose rising was supposed to coincide with the hot weather, is always spoken of as bringing pestilence and trouble. The connection between Sirius and the hot weather was one of the conventions of poetry which the Augustan writers had borrowed from the Greeks.
[LXVII.] The story referred to is that of the fifty daughters of Danaus, who were married to the fifty sons of Aegyptus, their cousins. Danaus ordered his daughters to murder their husbands on their wedding night, and they all obeyed except Hypermnestra, who loved her husband Lynceus, and so saved his life.