Watch List notes:

Gaius (Caligula), 37-41. Quadrans (Copper, 17 mm, 3.10 g, 6 h), Rome, 40-41. C CAESAR DIVI AVG PRON AVG around pileus flanked by large S C. Rev. PON M TR P IIII P P COS TERT around R C C. BMC 64. Cohen 7. RIC² 52. Sandy green over dark brown patina. Very fine.
From the collection of W. M. Stoecklin, Winterthur, Switzerland, acquired prior to 1981.