[13] On the Attic standard, adopted by Alexander, the Seleucid and Bactrian kings, the drachm weighed 67·5 grains; on the Persian standard, adopted by the Indo-Greeks (and hence in some works called the Indian standard), it weighed 88 grains, but their coins rarely reach the full weight. Mr. Whitehead, in a recent monograph, “The Pre-Muhammadan Coinage of North-Western India” (_Numismatic Notes and Monographs_, No. 13, The American Numismatic Society, New York, 1922), calls the two silver denominations of the Indo-Greeks drachms and tetradrachms, thus supposing a separate Indian standard. I have retained the hitherto accepted nomenclature, hemidrachms and didrachms for convenience of reference to standard works. Demetrios was the first Bactrian king to strike square copper coins of the Indian type, with a legend in Greek on the obverse, and in Kharoshṭhī on the reverse. His rival, Eukratides, struck these bilingual square copper pieces in greater abundance, as well as a very rare silver coin with inscriptions in both languages. The Gandhāra copper coinage of Agathokles and Pantaleon (Pl. II, 2) has already been alluded to. After the removal of the seat of government to territory south of the Hindu Kush, we find the coinage undergoing a radical change. The rare gold staters and the splendid tetradrachms of Bactria disappear. The silver coins of the Indo-Greeks, as these later princes may conveniently be called, are the didrachm (Pl. II, 5) and the hemidrachm. With the exception of certain square hemidrachms of Apollodotos and Philoxenos (Pl. II, 7), they are all round, are struck to the Persian (or Indian) standard, and all have inscriptions in both Greek and Kharoshṭhī characters. Copper coins, square for the most part, are very numerous (Pl. II, 6). The devices are almost entirely Greek, and must have been engraved by Greeks, or Indians trained in the Greek traditions, yet “the engravers ... were no slavish copyists of Western models, but were giving free and spontaneous expression to their own ideas.”[14] On the reverse is ordinarily to be found some god or goddess—Herakles, Zeus, Pallas, or some symbol of their worship; the “two piloi” (caps) of the Dioskouroi are of frequent occurrence. A notable square copper coin of Eukratides has the figure of a seated Zeus, accompanied by the legend in Kharoshṭhī, “_The city deity of Kāpiśī_,” suggesting that others of these deities may stand as the patrons of cities.[15] Other reverse devices are the tripod, a king on horseback, and various animals, including the specially Indian elephant and humped bull. The portraits on the obverse, especially on the fine didrachms, are realistic and boldly drawn, and show us clearly what manner of men these early European rulers in India were. On most of these coins and those of the Śaka rulers are found a great variety of monograms (Fig. 3) formed of Greek letters, but the significance of these has never been satisfactorily explained. From a study of