  We present Space Telescope Imaging Spectrograph emission-line spectra of the
central regions of the spiral galaxies NGC 1300 and NGC 2748. From the derived
kinematics of the nuclear gas we have found evidence for central supermassive
black holes in both galaxies. The estimated mass of the black hole in NGC 1300
is 6.6 (+6.3, -3.2) x 10^7 solar masses and in NGC 2748 is 4.4 (+3.5, -3.6) x
10^7 solar masses (both at the 95% confidence level). These two black hole mass
estimates contribute to the poorly sampled low-mass end of the nuclear black
hole mass spectrum.
