Hesseltinella, a new genus of the Thamnidiaceae is described with a single species, H. vesiculosa, isolated from Brazilian soil. Main characters of the new genus are branchlets, radiating from swellings of the sporangiophore and terminating in secondary swellings bearing single sporangiola. Further Mucorales isolated for the first time from Brazilian soils are: Absidia pseudocylindrospora, A. cylindrospora, A. corymbifera, A. cuneospora, A. blakesleeana, Choanephora circinans, C. infundibulifera, Cunninghamella elegans (syn.: C. batistae Upadhyay & Ramos), C. phaeospora, and Mortierella hyalina.