Cr 35/5 Æ cast Sextans

Rome, ca. 225-217 b.c.e.
o: Head of Mercury left, wearing winged petasus; •• value) below; on a raised disk
r: Prow of galley right; •• (value) below
35mm, 38.60 gm, 12h
The so-called "libral" Prow right series of cast bronze is most likely associated with the "quadrigatus" AR didrachms. The weights are generally under the mathematical equivalent of a Roman pound -- in the case of this specimen, a worn "sixth", would be 231 gms,, far short of the likely weight of the libra in the mid-320 gm range. Even account for wear and the chip at the casting sprue point, the weight would not be close to a "pound".
This photo is not great, the coin, is much nicer in hand.