Elmidae of Taiwan part I: two new species of the genus Stenelmis (Coleoptera: Dryopoidea) with notes on the group of Stenelmis hisamatsui

Two new species of Elmidae: Stenelmis wongi and Stenelmis formosana, belonging to the group of Stenelmis hisamatsui, are described and illustrated. Descriptions of their habitats and ecological information are also included. A key and checklist to the species of hisamatsui group are given.