The coin belongs to Group D of Series X (Class Va). While the obverse is of the Class V type, the reverse no longer has the cross in front the pony and is Class IV. Both V and IV are not really "classes" at all. They are earlier versions of the design Groups referred to above.
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Information on Group D
Explain the lyre symbol
c. John Hooker 1996 writer@writer2001.com
Here is an example of one of these coins.