Colonial variants of Microsporum gypseum apparently undescribed previously were obtained from a case of tinea corporis. One of these with a "red-silky" appearance has been named M gypseum var vinosum. In addition to the usual cultural studies, animal and human pathogenicity tests were performed and cultures unchanged in appearance were recovered from lesions. Application of a new technique in medical mycology, that of sexual mating of the strain in question to produce an ascomycetous stage, provided final confirmation of its specific identity, as cleistothecia of Nannizzia gypsea were formed.