Acanthostigma and Tubeufia species, including T. claspisphaeria sp. nov., from submerged wood in Hong Kong

Acanthostigma scopulum, Tubeufia claspisphaeria sp. nov. and T. paludosa were identified from submerged wood collected in a small forest stream on Lantau Island, Hong Kong. The collections of Acanthostigma scopulum and Tubeufia paludosa differed slightly from the original descriptions. Tubeufia claspisphaeria differs from previously described species in that it has hook-shaped setae that form radially around the ostiole. This new species is described and illustrated and compared with the most similar species. A dichotomous key to the 16 accepted species in Tubeufia is provided.published_or_final_versio