Tacitus,
Ancient mints struck a large number of
rare varieties. All commoner
types, and the
rare ones the cataloguer
had knowledge of, are recorded in the
standard catalogues. But that is usually nothing like a full report of every variety produced, and new ones tend to turn up quite frequently!
No need to regard the new variants as "
mules" or to think they must be irregular because not recorded before: in most cases they have just as much right to be considered normal and intentional as the variants previously known!
The
dupondius / As distinction is a special case for Caesars and for empresses up to
Mamaea, since there was no typological difference (
radiate crown or crescent below
bust), so only the metal color distinguishes the two
denominations. What exists is largely unknown, because
Cohen made no attempt to distinguish the
denominations, and Mattingly's attempt to do so in the
BMC footnotes is unreliable, since he relied primarily on
weight which is not a valid criterion.
