OBSERVATIONS ON THAMNIDIACEAE (MUCORALES) .6. 2 NEW SPECIES OF DICHOTOMOCLADIUM AND THE ZYGOSPORES OF D-HESSELTINEI (CHAETOCLADIACEAE)

Two new species are described in Dichotomocladium. One species with gl obose sporangiola, D. sphaerosporum, was isolated from dung collected in Mianwali, Pakistan, and is similar to D. elegans in its general hab it. The second species with obovoid sporangiola, D. floridanum, was is olated from dung collected in Gainesville, Florida, and resembles D. r obustum. The zygospores of D. hesseltinei have hemispherical suspensor s and are described for the first time. Chaetocladiaceae is revived fo r fungi having branched (dichotomous, verticillate) fertile hyphae, pe dicellate, unispored sporangiola which are produced on fertile vesicle s, and sterile spines. Dichotomocladium is transferred to Chaetocladia ceae, which contains only one other genus, Chaetocladium. Chaetocladiu m and Dichotomocladium each are considered monophyletic, and together comprise the monophyletic Chaetocladiaceae. Keys are provided to the g enera of Chaetocladiaceae and the species of Dichotomocladium. A list of families and genera currently included in Mucorales also is provide d.