Caligula, AR denarius, 2.94 g, 17.5 mm. Lyons. 37-38 AD.

C CAESAR AVG GERM P M TR POT, bare head right.
AGRIPPINA MAT C CAES AVG GERM, draped bust of Agrippina I
right, hair in a plait behind head. 

RIC 8; RSC 4; BMC 8; Kampmann 11.3

With permission of numislanz.de, Auktion 102, lot 472