Halide bulbs in parallel or series?

[christyf5]

yeah they are spread pretty even, i have mine mounted parallel just because of that huge piece that sticks out of the reflector (I"m having a morning moment here, can't think of what its called), anyhoo its got the cord and all that (like the socket bit) it doesn't fit for the width of my tank towards the front and I'd likely bonk my head on it so they're turned to the side

Jeez did any of that even make sense? Need more caffeine...