CHAPTER XII. The Greek System.

riding on a dolphin. This is the familiar type of the Tarentine didrachms which, from their first issue down to the invasion of Pyrrhus (450-280 B.C.), weigh normally 123-120 grs., although one specimen weighs 128 grs. This coin Mommsen recognized as the noummos of Aristotle. Professor Gardner afterwards suggested that the diobol, on which occasionally the same type is found, was rather the coin meant. Recently Mr A. J. Evans has almost proved this hypothesis impossible by showing that all the diobols yet known are probably later than the time of Aristotle⁶⁸. As, however, this rests on negative evidence, and is liable to be overthrown at any moment by the discovery of an archaic diobol, it is advisable to cast about for some more positive criterion. Heraclea of Lucania, the daughter-city and close neighbor of Tarentum, as we know from the famous Heraclean Tables (which scholars are agreed in regarding as written about the end of the 4th cent. B.C.), employed as a unit of account a silver nomos. It is so probable that the nomos employed at Heraclea (circ. 325 B.C.) would be the same in value as that employed at Tarentum in the time of Aristotle (ob. 322 B.C.), that if we can prove the nomos of Heraclea to be