There are at least three
rev. dies showing this arch between the two pediments supported by columns:
cf. your coin, the
Gorny specimen you refer to, and
Paris pl. CXIV, 466.
The arch between the two triangular pediments was already pointed out by
Cohen 91 in
his description of the
Paris coin: "dans le fond, un temple à quatre colonnes à deux frontons triangulaires, soutenus chacun
par deux petites colonnes et un fronton cintré" = "in the background, a temple of four columns with two triangular pediments, each of which is supported by two small columns, and an arched
pediment".
It would have been clearer if
Cohen had written, "in the background, a temple of four columns, with an arched
pediment in the center, between two triangular pediments left and right, each of which is supported by two small columns".
A feature which is clearer on the
Paris specimen than on yours and Gorny's: the horizontal beam through the whole temple just above the heads of the two musicians, which cuts off the two middle columns in each of the triangular pediments, explaining why
Cohen called these columns "small". According to
Hill,
Rome Congress 1961, Atti, p. 279, there are thinner columns and a horizontal beam in the other
type too, but only partially rendered, and indeed hardly visible in
his photo (pl. XX.7). He considers these
dupondii to represent the sacrifice to the goddesses of childbirth before a wooden theater on the Campus
Martius on the second night of the
Ludi Saeculares, but cannot explain the two variants of the
type: either two views of the same building, or the rarer variety is an inaccurate version which was withdrawn. Two circular pediments between two triangular pediments, each supported by two columns, in the second story of a
portico on a
provincial coin of Neocaesarea in
Pontus:
Price and Trell, Fig. 71. There is doubtless more recent bibliography on the question, with which I am unfortunately not familiar. Certainly these two variants of the
type deserve separate numbers in
RIC.