Abstract
During the present investigation evidence was obtained to indicate that porcine P. haemolytica-like strains were sufficiently different from P. haemolytica sensu stricto to constitute a new taxon within the family Pasteurellaceae. Thirteen strains formed a homogenous group tentatively designated taxon 15. The final taxonomical position of taxon 15, however, has to await further taxonomical investigations, including determinations of mol % G + C in DNA and DNA:DNA hybridizations. A species name has not been suggested for the same reasons.