  We have cross-correlated X-ray catalogs derived from archival Chandra ACIS
observations with a Sloan Digital Sky Survey (SDSS) Data Release 2 (DR2) galaxy
catalog to form a sample of 42 serendipitously X-ray detected galaxies over the
redshift interval 0.03 < z < 0.25. This pilot study will help fill in the
"redshift gap" between local X-ray-studied samples of normal galaxies and those
in the deepest X-ray surveys. Our chief purpose is to compare optical
spectroscopic diagnostics of activity (both star-formation and accretion) with
X-ray properties of galaxies. Our work supports a normalization value of the
X-ray-star-formation-rate (X-ray-SFR) correlation consistent with the lower
values published in the literature. The difference is in the allocation of
X-ray emission to high-mass X-ray binaries relative to other components such as
hot gas, low-mass X-ray binaries, and/or AGN. We are able to quantify a few
pitfalls in the use of lower-resolution, lower signal-to-noise optical
spectroscopy to identify X-ray sources (as has necessarily been employed for
many X-ray surveys). Notably, we find a few AGN that likely would have been
misidentified as non-AGN sources in higher-redshift studies. However, we do not
find any X-ray hard, highly X-ray-luminous galaxies lacking optical
spectroscopic diagnostics of AGN activity. Such sources are members of the
"X-ray Bright, Optically Normal Galaxy" (XBONG) class of AGN.
