1. INTRODUCTION  
2. DATA  
2.1. HectoMAP: A Dense Spectroscopic Survey  
2.2. Search for X-ray Emission in the ROSAT All-Sky Survey  
3. CLUSTER IDENTIFICATION  
3.1. The FoF Algorithm  
3.2. X-ray Counterpart of FoF Clusters  
3.3. Caustic Method and Cluster Membership  
4. A CATALOG OF HECTOMAP FOF CLUSTERS WITH X-RAY EMISSION  
5. DISCUSSION