Maximinus II Heraclea??

I need a little help with this one

obverse inscription appears to be: IMP C GAL VAL MA(XIMI)NVS PF AVG
rev inscription looks like: GENIO IMPERATORIS with mintmark either HTB or MTB
star in left field and crescent in right
any thoughts? RIC# ?

I think the obverse legend is MAXIMIANVS. See these Google Image results.

You will also recognize the reverse in some of the images, which is of the GENIO IMPERATORIS type.

This is pretty surely Emperor Galerius. The pictures are dark but I can read the name GAL(erius) VAL(erius) MAXIMIANVS.
This coin fits it I would say:
http://wildwinds.com/coins/ric/galerius/_heraclea_RIC_048a_B.jpg