On the Properties of 21 X-Ray Globular Clusters in M31

B and V plates for 19 fields covering a 4 x 4 deg area centered on M31 have been obtained with the Loiano 152-cm Ritchey-Chretien F/8 telescope. A search for globular clusters is being carried out, yielding 240 candidates in the central field (70 x 70 arcmin). Twenty-one candidates of this sample have been identified with 17 HRI and 4 IPC X-ray sources derived from Einstein Observatory data. This paper presents results of the analysis of the properties of these 21 sources in comparison with those of other clusters in M31 and in the Galaxy.