The silver-based Armorican coins, which are attributed to the tribe of the Coriosolites, have been found in a great number of hoards. J. B. Colbert de Beaulieu, in his study of this coinage, divided it into six types defined by details on the obverse. The hoard of Trebry, discovered in 1973, with its 1700 coins, has provided an opportunity for carrying out neutron activation analysis on one hundred coins, a sampling which may be considered as coherent and reasonably representative of the types. The correction factors for self-shielding, shadow effects, and counting geometry were measured experimentally on silver-copper alloys specially prepared with a composition range including the actual compositions for silver. The analytical results corroborate for the most part the typological classification except for one type. The possibility of successive devaluation indicates a simplification of the relative chronology of this coinage. -- AATA