The catalog is a compilation of cross-identifications between the numbering system of Mermilliod (1978) for stars in open clusters and the numbering systems of several other astronomical catalogs, including HR, HD-HDE, DM, LS, LSS, GCVS, IDS, ADS, SAO, and several smaller lists. Also included are files listing the inverse cross-identifications from each catalog to the Mermilliod (1978) numbers. This version updates and expands the version presented by Mermilliod (1976A&AS...23..419M). The catalog is in 13 files: the first file contains the main cross- identification list from the Mermilliod (1978) system to the other catalogs; the next 11 files contain the inverse lists from the catalogs to Mermilliod (1978); and the thirteenth file contains a list of the references adopted for the individual star numberings for each cluster used by the Mermilliod (1978) system.