Ada-kahapana is the name for half of a Kalanda of Gold.This is extremely rare and not more than five coins have been published.
In Ceylon- Coins and Currency HW Codrington describes one type
12. Obv. : Standing figure, r. A semicircular line from top to back of head, ending at the bottom in a thickened line. Right arm pendent ; left, bent, with forearm at right angles to body, holding a Vase, over which a chank, cf. reverse of kahavanuva I B (1). Legs bent, ; r ;dhoti, flowing at either side but no line between legs .To l. standing lamp outside arm ; to r. a squat fire-altar, All in bead circle.
The meaning of the Ka is not clear the pagination of the palm-leaf manuscripts, as well as in the Kata-paydadi system of notation, it stands for ” one.” The half kahavanuva, perhaps, may have been the theoretical ,: Sinhalese coinage, just as the Kasu or half madai was of the Cola.
Two Adakahapanas was published by Mr OMR Sirisena in his book MEDIEVAL GOLD COIN OF SRI LANKA. One is of the similar type as Chank over pot published by Codrington.The other is unique and is of the Bo-Ankula type I.
The gold Coinage of Mediveal Sri-Lanka
The legend on the Pala or Quarter Kalanda of Gold