Augustus (Prima Porta) Adlocvtio
ADLOCUT[IO] COH[ORTIUM], a highly original type that shows the new emperor addressing a group of five soldiers (RIC 32f). This type presumably refers to the donative Caligula gave to the Praetorians on his ascension. The sestertius may have been struck as a commemorative and distributed among the soldiers. He was the first emperor to acknowledge a debt to the guards.
The Caligula OB/CIVES/SERVATOS Sestertius also with the weak argument that because SPQR is on the reverse that should suffice for the lack of the S.C.
Gaius Caligula. 37-41 AD. Æ Sestertius (29.80 gm). Struck 37-38 AD. [C] CAESAR. AVG. GERMANICVS. PON. M. TR. POT., laureate head of Caligula left / S. P. Q. R / P. P / OB. CIVES. / SERVATOS, legend in four lines in oak wreath. RIC I 37; BMCRE 38, Cohen I 24.
Sestertii of Caligula are not rare, but do command a premium in today's market, particularly in the outstanding condition of this coin. During Caligula's short reign, only 4 types of Sestertii were issued in his name: 1) ADLOCVT COH, Caligula addressing soldiers; 2) AGRIPPINA, DRVSILLA, IVLIA, SC, Caligula's three sisters; 3) SPQR OB CIVES SERVATOS, legend in four lines within wreath; 4) DIVO AVG, S-C, Gaius sacrificing before hexastyle temple. The types were repeated each year with changing obverse inscriptions. A fifth type was issued in Agrippina Sr.'s name which has her bust on the obverse and a carpentum on the reverse.
Over the years, I have probably handled 100 of the these coins and have never given them much thought, after all the type is rather dull. Coming up with something interesting to write though raised a question. It is interesting to note that all the current standard references for this sestertius fail to mention the fact that it lacks the usual designation of SC typically found on sestertii. They all make special note of the Adlocutio type which also lacks the SC and suggest that it must have been a special issue struck by Caligula from ae acquired from some source other than the aerarium, but none mention this type. Was it also struck from ae acquired from another source, or is their another explanation for the lack of SC? Both types were issued throughout Caligula's reign and the SC is never added. Were these special issues every year? That to me seems difficult to believe. Perhaps these two issues were Caligula's first issues and there was some confusion as to whether SC belonged on them at all; these were the first Rome mint sestertii to carry and emperor's portrait on the obverse and it may have been seen as disrespectful. The lack of SC on the reverse lead Gnecchi to conclude that this type was a medallic issue and he included it in his work on Roman medallions. Anyway, something to think about.
I believe this coin as Gnecci concludes that the OB CIVES SERVATOS type was a medallic issue.
1. Brian Murphy's- Coin of the week Article
2. Portraits of Caligula: The Seated Figure? Joe Geranio SAN Volume Vol. XX, No. 1 (1997)