Agrippa - issued by Gaius [Caligula] (37-41 A.D.) - Copper As - 27mm, 9.18g
Obverse - M AGRIPPA L F COS III
Agrippa, his head left, wearing rostral crown.
Reverse - S C
Neptune standing left, wearing cloak, holding trident and small dolphin.
Image
Minted in Rome between 37 and 41 A.D.

Reference:
Sutherland, C.H.V., "Roman Imperial Coinage", Volume 1, revised edition(RIC), p112, nr.58 (under Caligula).
Sear, D.R., "Roman Coins and their Values" (RCV Millennium Edition), Volume 1, p358, nr.1812.
Sear, D.R., "Roman Coins and their Values" (RCV 4th Revised Edition),p101, nr.556  (under Agrippa).
Cohen, H, "Descriptions Historique des Monnaies frappees sous l'Empire Romain" (C), Volume 1, p75, nr 3 (under Agrippa).
Mattingly, H., "Coins of the Roman Empire inthe British Museum", Volume 1 (BMCRE), p142-3, nr. 161-166. (Tiberius)
Van Meter, D., "Handbook of Roman Imperial Coins" (VM), p74, nr. 4 (under Agrippa).
Suarez, R., "Encyclopedia of Roman Imperial Coins II" (ERIC II),  p22,nr.4 (B1, O1, R3, T1) (under Agrippa).
Suarez, R., "Encyclopedia of Roman Imperial Coins II" (ERIC II-eBook),  p20,nr.4 (B1, O1, R3, T1) (under Agrippa).
Kampmann, U., "Die Münzen der Römischen Kaiserzeit", 2e Auflage (Kampmann), p58, nr.11.9. (under Agrippa).

Quality: Fair+/Fine-