Pana
An early copper coin of Ceylon. It is referred to in works of the fifth century and later, and is frequently alluded to under the name of Kah?pana.
The English traveller, Robert Knox, who was in Ceylon from 1659 to 1679, and whose writings were published in 1681 by order of the East India Company, states that " the King's proper coin is called a pounam (panam); it is as small as a spangle; 75 make a piece of eight, or a Spanish Dollar. " See also Rhys Davids (sees. 14-18).
In the coinage of ancient India the Pana, or Karshapana, as it is sometimes called, was based on the weight of eighty rati seeds, equivalent to one hundred and forty-four grains, or nearly nine and a half grammes. The name, like the Greek Drachma, means a " handful, " and is derived from pani, the hand. See Cunningham (pp. 4-5, and 42-44).
The following table exhibits the names and weights of the early Indian coins in detail: [see chart]
Source: Frey's Dictionary (American Journal of Numismatics, Vol. 50, 1916)
Table: https://archive.org/stream/AJN1916Vols50to50#page/n185/mode/2up/