Globular clusters at the distance of M31 have apparent angular sizes of a few arcseconds .
While many M31 GCs have been detected and studied from ground-based images , the high spatial resolution of HST allows much more robust detection and characterization of star cluster properties .
We present the results of a search of 157 HST/WFPC2 images of M31 , We found 82 previously-cataloged globular cluster candidates as well as 32 new globular cluster candidates and 20 open cluster candidates .
We present images of the new candidates and photometry for all clusters .
We assess existing cluster catalogs ’ completeness and use the results to estimate the total number of GCs in M31 as 460 \pm 70 .
The specific frequency is S _ { N } = 1.2 \pm 0.2 and the mass specific frequency T = 2.4 \pm 0.4 ; these values are at the upper end of the range seen for spiral galaxies .