Abstract
Mycoplasmas isolated from the conjunctivas and nasopharynges of rats and mice were shown to be serologically distinct from 78 previously recognized Mycoplasma and Acholeplasma spp. Three cloned strains obtained from separate animal colonies were examined in detail. These strains were indistinguishable from each other. Strain 58B (= NTCC 10197) is designated the type strain of a new species, M. collis.