Specific mass S _M = 100( M _GCS/ M _dyn) vs. host galaxy mass. Solid dots are dynamical masses M _dyn calculated from ( R _e , σ _e ), while open circles are masses estimated from L _V and Equation (3), for galaxies without measurements of R _e and σ _e . The solid diagonal line at upper right shows the effect of changing M _dyn by 1.0 dex (an increase in M _dyn yields a proportionate decrease in S _M ~ M _GCS/ M _dyn). The horizontal line at S _M = 0.1 is the approximate average level reached for the intermediate-luminosity galaxies where star formation is maximally efficient. Eighty percent of all galaxies fall below the dashed horizontal line at S _M = 0.3 (see text). The superimposed curve is the interpolation model fit discussed in Section 4.2.