Obviously thinking about parallels to Roman or otherwise aes grave.
Largely CAST!, typically dated to 450-415 period. 3-pellet type most common= Trionkion or Tetras. 4-pellet also known = Trias or tetronkion. 2-pellet = Hexas
There also silver fractions with five pellets usually dated to the early 5th century
also has cast bronze denominations with 1, 2, 3, 4 pellets. 6 pellets are known in struck coinage.
The “Onkia” doesn’t have a denomination mark, but it’s fab design is clearly intended to flag its place in the denomination system:
2 – pellet:
Struck variations also exist:
3-pellet typically dated 420-405 BCE seems most common
1-pellets are also known
Himera, last quarter of the fifth century onwards (links to ANS specimens)
Base-12 system, six-pellet, three pellet seem most common, some four pellets
Gela, last quarter of the fifth century – links to specimens in trade
3-pellet and 1-pellet seem most common, assume this means a base-12 system too
Syracuse, last quarter of the fifth century – links to specimens in trade
3-pellet and 1-pellet seem most common, again I assume this means a base-12 system
Some mints producing struck Hemilitrons with pellets
Lipara, Syracuse (many AR with four spoked wheel), Akragas, Piakos, Mytistratos (mid 4th cent?), Panormos (fine rooster! and some with Punic script), Himera, Mamar, Solus (Solos, Soloi), Kamarina (?), Naxos (also silver version), Entella, Leontini, Kentoripai
4-pellet piece from Segesta misidentified as hemilitron, also Motya AR piece,
Some Bibliography on Denomination systems
La valeur des monnaies grecques en bronze / Olivier Picard. Revue Numismatique Vol. 153, 1998, p. -18.