Cambridgeshire 18, County (Dalton & Hamer, page 6)Denomination: halfpenny, scarcity: Scarce
18. O: A Druid's head. The rev. of No. 12 (Corrigenda, page 552). R: A figure of Britannia seated, 1797. See Middlesex. E: Plain. 18a. E: PAYABLE IN LONDON, and engrailed. No. 18, Scarce. 18a, RR.
Comments about this tokenReverse image from Middlesex 990, page 189. Hope it's correct.