Lancashire 17, Lancaster (Dalton & Hamer, page 65)

Denomination: halfpenny, scarcity: Rare (R)
Dated 1791.

17. O: The bust closer to I of IOHN, and star under the centre of ermine. 
       (Same as No. 16.)
    R: Line of shield between C and A to left, and centre of E to right. 
       (Same as No. 14.)
    E: PAYABLE AT THE WAREHOUSE OF THOS. WORSWICK & SONS . X .

No. 17, R.

The points noted as a mode of identification:
O: The position of the front point of crown to the letters of the word "GAUNT,"
   and the centre point of crown to the letters of the word "DUKE," also the
   star under bust.
R: The centre line of shield to the letters on either side, and point of shield
   to the date.

Keywords

iohn of gaunt duke of lancaster,lancaster halfpenny,1791