It is of the close of the epoch of Marcus Aurelius or the earlier years of the reign of Commodus. The style is that of the Græco-Roman art. The work is very beautiful for that epoch, and there rests in this head of the master of the gods an accent of grandeur in which one feels the reflection of the original Greek of the better centuries, imitated here by the engraver of the Græco-Roman age. [Illustration: SOMMERVILLE COLLECTION. JUPITER ÆGIOCHUS.] It is an interesting circumstance, which merits particular attention, that the cameo Zulian coming from Ephesus and this Jupiter Ægiochus are certainly of the workmanship of Asia Minor. Early in this century this cameo made part of the celebrated Northwick Collection of England. Afterwards it was acquired by a wealthy connoisseur in France, and later passed into the possession of M. Feuardent, Paris, when, with his permission, an engraving of it appeared, with five quarto pages of text and notes, in the _Gazette Archæologique_, Paris, 1877, edited by Baron J. De Witte, Membre de l’Institut and François Lenormant. M. Adrien Longperier, the distinguished glyptologist and savant of the Institut de France, some thirty years ago made a study of this gem, and seriously contemplated its acquisition for France; he urged the French Government to authorize its purchase for the collection in the Salle des Pierres gravées in the Bibliothèque Nationale, Paris, or for the Museum of the Louvre. Several other museums also negotiated for its purchase, but the late owner being firm in his demand, the price caused them to delay, and now it belongs to America, being part of my collection. THE TRIUMPH OF CONSTANTINE. Among the most important and interesting antique gems in my collection is one engraved when Constantine held the Roman Empire in Byzantia, which came into the possession of the Court of Russia. The Empress Catherine II., wishing to confer a great favor and special reward on an ambassador to her court from her remarkable collection in the Museum of the Hermitage at St. Petersburg, presented this antique gem to him in 1785. Twenty-five years afterwards, at his death in Greece, it was sold, and was piously guarded during thirty years by a collector in the Hellenic peninsula. After that it became the property of Bieler in Styria. I came into possession of this remarkable gem after more than five years’ negotiations with its owner, and subsequently with his heirs. It is a cameo of great importance in itself. Prof. C. W. King, of Trinity College, Cambridge, England, said, “It is by far the most important of all similar works of the Lower Empire hitherto published.” It is of very considerable dimensions (6 × 4 inches), being the eleventh in point of magnitude of those already existing in any cabinet. It is a maculated sard, dark-reddish amber color, with slight white, dark sepia, and burnt sienna spots or maculation.