  The vast majority of optically identified active galactic nuclei (AGNs) in
the local Universe reside in host galaxies with prominent bulges, supporting
the hypothesis that black hole formation and growth is fundamentally connected
to the build-up of galaxy bulges. However, recent mid-infrared spectroscopic
studies with Spitzer of a sample of optically "normal" late-type galaxies
reveal remarkably the presence of high-ionization [NeV] lines in several
sources, providing strong evidence for AGNs in these galaxies. We present
follow-up X-ray observations recently obtained with XMM-Newton of two such
sources, the late-type optically normal galaxies NGC 3367 and NGC 4536. Both
sources are detected in our observations. Detailed spectral analysis reveals
that for both galaxies, the 2-10 keV emission is dominated by a power law with
an X-ray luminosity in the 10^39 - 10^40 ergs s^-1 range, consistent with low
luminosity AGNs. While there is a possibility that X-ray binaries account for
some fraction of the observed X-ray luminosity, we argue that this fraction is
negligible. These observations therefore add to the growing evidence that the
fraction of late-type galaxies hosting AGNs is significantly underestimated
using optical observations alone. A comparison of the mid-infrared [NeV]
luminosity and the X-ray luminosities suggests the presence of an additional
highly absorbed X-ray source in both galaxies, and that the black hole masses
are in the range of 10^5 - 10^7 M_solar for NGC 3367 and 10^4 - 10^6 M_solar
for NGC 4536.
