The Triens denomination
The triens (plural trientes) was an Ancient Roman bronze coin produced during the Roman Republic valued at one-third of an as (4 unciae).

The most common design for the triens featured the bust of Minerva and four pellets (indicating four unciae) on the obverse and the prow of a galley on the reverse. It was not a common denomination and was last struck c. 89 BC.
Triens

(1) Anonymous After 211 BC
Obverse: Helmeted head of Minerva right. Four pellets above.
Reverse: Prow right, ROMA above, four pellets below.
Ref: Crawford 56/4, RBW 206.
(2) L. Sempronius Pitio 149 (148)BC
Obverse: head of Minerva right wearing crested helmet; ●●●●
Reverse: prow of galley right; L·SE(MP) / ●●●● / ROMA
Ref: Crawford 216/4
(3) Rome | Anonymous 208 BC
AE Triens Etruria
Obverse: head of Minerva right wearing crested helmet; ●●●●
Reverse: prow of galley right; ROMA / ●●●●
Ref: McCabe E1.Tr.1 (related to Crawford...