The Collaborative International Dictionary of English v.0.48:

Carolus \Car"o*lus\, n.; pl. E. Caroluses, L. Caroli. [L.,
   Charles.]
   An English gold coin of the value of twenty or twenty-three
   shillings. It was first struck in the reign of Charles I.
   [1913 Webster]

         Told down the crowns and Caroluses.      --Macawlay.
   [1913 Webster]