Gallienus, AE Antoninus, Rome. Sole reign.

Obv: GALLIENVS AVG, radiate, cuirassed bust right
Rev: NEPTVNO CONS AVG, Hippocamp springing left. 
N in exergue.

Göbl 742u; VM.178/2

Note: Not in RIC with hippocamp springing left (RIC = 
springing right) and no actual example listed in 
Göbl (= the rad. cuir. column is empty)

Courtesy of Jim of www.lunalucifera.com/Zoo/