They are piecs of silver all cut or cast to a shape, circular, Oval ,square etc if you look on which Marks were struck. These 5 marks of a few coin is described below
Descendent of Adjasattu.
The Series II & III coins were attributed to have been minted during the rule of the successors of Ajatsattu.After another 24 years his son Udayabhadda reigned for 14 years and the dynasty rule ended with Nagadasaka. The Dipavansa states that 8th year of the reign of Ajatasattu the Buddha attained parinibbana.The period these coins were issued the Kings who ruled in Sri Lanka were Vijaya, Panduvandeva and Abaya.
A Coin perhaps of Series II which rquires identification.
1A new coin published by Raja Wickremasinghe is not in Gupta & Hardekar list of 1990’s.
The Sun symbols is GH No differs from 269, 284 and 313[ GH no
The Spear with two arrow heads in Rectangle with fish in coin Types 269 is GH No ,284 is GH No and 313 is GH No .The symbol is different .
The Double Fish symbol GH No is on 269, 284.
The six armed symbol GH No is on 282 etc but not on 269[ GH No or 284[ GH No ].
The symbol to bottom left ???
The coins agree in size of the corresponding coin type published by PL Gupta & Hardaker.They are approximately dated to series II 435-425 BC and series III to 430-410 BC , by Gupta & Hardaker.