From a discussion on Forvm Ancient Coins.

Constantius Gallus AE2, 24mm.

Obverse legend is DNCONSTANTI-VSNOBCAES.
Rev: FEL TEMP RE-PARATIO, Gallus holding labarum in his 
left hand and Victory in his right, "spurning" a captive.
Gamma in left field, star right.
Mintmark is star TS Delta (or A) dot (179). 
Rated Scarce 
RIC VIII Thessalonica 179
(unlisted officina if A)

These were only made in Thessalonica and there 
are 4 different types of them (2 different with 
NOB CAES but Thess 170 had TS Epsilon and 2 
different with DN CONSTAN-TIVS PF AVG


David Sear commented: 

"I have taken a look at your coin of Constantius 
Gallus and it would certainly seem to coincide 
with RIC 179 except for the missing star 
preceding the mint name. 

The mint mark TS/officina/pellet appears to be 
unrecorded and one is tempted to suspect that 
the omission of the star is a die-engraver's 
error. Otherwise, it would represent a 
previously unknown issue which is certainly 
possible given the rarity of the type for 
Gallus. 

Incidentally, I believe the officina letter is 
probably beta rather than alpha. If you compare 
it with the "A"s in the obverse and reverse 
legends you will find that they have flat tops 
while the officina letter has a curved top. 

I hope this is of some help to you.

Sincerely,

David R. Sear"

So I've either got an unlisted officina for RIC 
179 or else a previously unknown issue.

Contributed by John Knisely, October, 2003.