Σικελῶν τινες—the S were a Latin tribe, and were driven from Latinm into Bruttium, whence they were again driven over to Sicily by the Opicans.
προσχωρεῖν—the greater part of the S. had supported the Athenians through enmity with Syracuse since 451 B.C., when the Sicel lcader Ducetius had defeated the combined forces of Acragas and Syracuse.
Ἀρχωνίδου—he had aided Ducetins in founding Calacte on the N. coast of Sicily. When D. died in 440, Syracuse feared that A. would revive the power of the Sicels, and so made war on them.
ταύτῃ—i.e. those of Northern Sicily.
τινῶν—A. was prince of Herbita, and his territory, or at least his influence, probably extended to Calacte on the north coast.
ἐκ Λακ. . . . ἥκειν—here ἥκω expresses come duly to their assistance, as in βοήθεια ἥξει III. 4; c. 16.3; ὠφελία ἥξει VI. 93. Cf. VI 73 ἐς τὴν Λακεδαίμονα πρέσβεις ἀπέστειλαν ὅπως ξυμμαχία αὐτοῖς παραγένηται. The word ἥκω is constantly so used in drama, esp. in addressing persons who have come to bring help.
προθύμως—cf. VI. 18 π. παραγίγνεσθαι, and c. 66 and 70 π. ἀντιλαβέσθαι.