When I got this coin, I could not remember why I bought it in the first place. After looking at it for a bit, I remembered that it was because it has a sceptre (or reversed spear) over the shoulder, instead of the normal spear. Unfortunately I can't make out the exergue clearly enough to give a confident RIC number. The second coin below is another example that I got years ago. The last picture shows a fairly typical representation of the spear with point.
Constantine I
A.D. 319
18x19mm 2.4gm
CONSTANTINVS AVG -- high crested helmet, cuir., spear across r. shoulder, shield on left arm
VICT• LAETAE PRINC PERP -- two Victories stg., facing one another, together holding wreath inscribed VOT PR on altar inscribed with the letter S.
In ex. [?]ESIS[?]