The Nomos denomination
The Nomos was an ancient Greek silver denomination weighing approximately 8 grammes.

It was roughly equivalent to the Attic didrachm or the Achaean stater, and is most often used about coins struck in Magna Graecia, especially Italy.
Nomos

(1) Taras 280-272 BC
Obverse: Nude youth crowning himself on horse standing right; capitol of Ionic column below; IΩ / IAΛO
Reverse: Taras seated on dolphin left, holding akrostolion and spindle; ANϘ / TAPAΣ
Ref: HN Italy 1014, Vlasto 803 ff.; SNG ...
(2) Tarentum 281 - 272 BC
Obverse: Nude warrior on horseback left, carrying small round shield
Reverse: Taras seated on dolphin left, holding Nike in right hand; waves below.
Ref: Vlasto 684-686; SNG ANS 1060
(3) Tarentum c. 302-280 BC
Obverse: Rider on horse holding shield and two spears; Greek text to upper left (ΦΙΛΩΝ) and lower left (ΕY)
Reverse: Man riding dolphin above waves; Nike in right hand; Greek text to the upper right (TAPAΣ)
Ref: Vlasto 683; SNG ANS 1059; Historia ...
(4) Tarentum | Ari 332 - 302 BC
Obverse: Nude, helmeted warrior on horseback to right, holding spear in right hand and shield and two more spears in left hand; [Ξ] in left field, [API] below horse
Reverse: Taras astride dolphin to left, holding oar in left hand and a kantharos in outstretched right hand, KΛ below dolphin, [TAPAΣ] to right.
Ref: HN Italy 939; Vlasto 636
(5) Thourioi c. 400-350 BC
Obverse: head of Athena right wearing crested Attic helmet decorated with Skylla; E
Reverse: bull butting right; fish swimming right below; ΘOYPIΩN
Ref: HN Italy 1783; cf. SNG ANS 1015
(6) Velia 334-300 BC
Obverse: Head of Athena left, wearing a crested Phrygian helmet decorated with a Centaur
Reverse: (KE) monogram of Kleudoros Lion standing left devouring prey A / Φ YEΛHTΩN (unreadable)
Ref: Williams 328 (O174/R244); HN Italy ...