The Delphin Classics was an edition of the Latin classics, intended to be comprehensive, which was originally created in the 17th century.
The 25 volumes were created in the 1670s for Louis, le Grand Dauphin, heir of Louis XIV (Delphin is the adjective derived from dauphin), and were written in Latin. Thirty-nine scholars contributed to the series, which was edited by Pierre Huet with assistance from several co-editors, including Jacques-Bénigne Bossuet and Ann Dacier. Each work was accompanied by a Latin commentary, ordo verborum, and verbal index. The editors added many notes and appendixes.
The original volumes each have an engraving of Arion and the Dolphin, and the appropriate inscription in usum serenissimi Delphini (for the use of the most serene Dauphin).
There is a reference to them in Part I, Chapter 5 of Thomas Hardy's Jude the Obscure, where young Jude, trying to educate himself by reading while delivering bread from a horse and cart, "plunge[s] into the simpler passages from Caesar, Virgil, or Horace [. . .] The only copies he had been able to lay hands on were old Delphin editions, because they were superseded, and therefore cheap. But, bad for idle school-boys, it did so happen that they were passably good for him."