It is very remarkable that the Etruscan coin of the second series, marked 2½, is only very slightly heavier than the Roman sesterce (_sestertius_) which bears a similar mark. Hence it has been very reasonably inferred that when the Romans set about the coinage of silver, they simply adopted with slight modification the silver system employed by their neighbours across the Tiber. This is all the more probable, as it is almost certain that, though Rome did not strike silver she like Athens before the time of Solon, and like Syracuse, used freely the coins of other communities for a long time previously. The Etruscan coins would therefore serve as silver currency at Rome. We may then assume that the monetary system must have been much the same on both sides of the river. Accordingly, since in 268 B.C. we find the Romans striking a coin in silver representing 10 copper _asses_, which is almost the same in weight as the Etruscan coin marked 𐌢, we may reasonably infer that, if the Romans had commenced coining silver a century earlier, their _denarius_ or 10-_as_ piece would have been the same weight as the Etruscan. [Illustration: FIG. 55. Didrachm of Tarentum.] Now besides the _litra_, which we found to be both a copper-unit and a silver coin in Sicily, there is another term of great interest, especially as it plays an important part in the history of Roman money. The general Latin name for a coin is _numus_, which in the later days of the Republic usually meant a _denarius_ when used in the more restricted sense, but in the earlier period it was the term specially applied to the silver sesterce (_sestertius_). This is almost certainly a loan-word, for Pollux is most explicit in warning us that, although the word seems Roman, it is in reality Greek and belongs to the Dorians of Sicily and Italy[430]. It is always a name of a coin of silver in Sicily, being so used by Epicharmus. The coin meant by this poet cannot have been one of great value, for he says: “Buy me a fine heifer calf for ten _nomi_.” It was in all probability the Aeginetan obol, for Apollodorus in his comments on Sophron set it down at three half (Attic) obols, that is, almost 17 grs. This is confirmed by the fact that an Homeric scholiast makes the small talent weigh 24 _nomi_, which gives nearly 17 grs. as the weight of that unit. Crossing into Italy, we find that according to Aristotle[431] there was a coin called a _noummos_ at Tarentum, on which was the device of Taras 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