  We present optical photometry of the low mass X-ray binary systems GX 349+2
and Ser X-1. Extensive VRI photometry of the faint optical counterpart (V=18.4)
to GX 349+2 reveals a period of 22.5 +/- 0.1 h and half-amplitude 0.2 mag. This
result confirms and extends our previously reported 22 h period. No color
change is detected over the orbit, although the limits are modest. We also
report the discovery of two new variable stars in the field of GX 349+2,
including a probable W UMa system. Ser X-1 is one of the most intense
persistent X-ray burst sources known. It is also one of only three burst
systems for which simultaneous optical and X-ray bursts have been observed. The
faint blue optical counterpart MM Ser (B~19.2) has long been known to have a
companion 2.1" distant. Our images indicate that MM Ser is itself a further
superposition of two stars, separated by only 1". At the very least, the ratio
of inferred burst to quiescent optical flux is affected by the discovery of
this additional component. In the worst case, the wrong object may have
previously been assumed as the optical counterpart.
