We propose to use the ISO Long Wavelength Spectrometer to measure
 the [C II] 158 micron and [N II] 122 micron emission from a
 sample of low mass Virgo Cluster spiral galaxies.  These galaxies
 have high star formation rates relative to their CO luminosities,
 compared to Galactic star formation regions and high mass spirals.
 This effect may be caused by either higher star formation efficiencies
 (SFR/M(H2)) in the lower mass galaxies, or higher N(H2)/I(CO) ratios
 relative to the Galactic conversion factor, due to low metallicity
 and dust content.  If this second possibility holds, we expect to find
 high [C II]/CO ratios in these galaxies, relative to high mass
 galaxies and to Galactic star forming regions, as has been found
 for dwarf irregular galaxies.  The [N II] observations will be
 used to distinguish between [C II] emission from neutral and
 ionized gas.