Crawford 200/3, Roman Republic, 155 BC., Rome mint, NAT-series (moneyer Pinarius Natta?), Æ Semis.

Roman Republic, NAT-series (moneyer Pinarius Natta?), Rome mint, ca. 155 BC.,
Semis (ø 25-27 mm / 10,76 g), bronze, axes irregular alignment ↑↗ (ca. 60°),
Obv.: laureate head of Saturn r., value mark S behind.
Rev.: NAT / S / ROMA , prow of galley right; S (value mark) to right, NAT above; below, ROMA.
Crawford 246, 200/3 (scarce, citing 7 specimens in Paris) ; Babelon Pinaria 4 ; Syd. 383a ; BMC 766 .

the moneyer is perhaps a Pinarius Natta, not otherwise known.