Massarina proprietunicata sp. nov., is described and illustrated based on a specimen occurring on submerged wood in the Lam Tsuen River, Hong Kong. It is characterized by verrucose ornamented ascospores bearing a narrow mucilaginous sheath, which is drawn out at the poles to form tapering appendages, with thickened and arrowhead-like tips. Massarina proprietunicata is compared with other aquatic Massarina species having ascospores bearing a narrow mucilaginous sheath or polar appendages. Details of morphology are illustrated with interference and scanning electron micrographs.