Semperula tailandensis, sp.n. from Salaya, Nakhon Patom Province, Tailand, is described upon a sample of 35 specimens, deposited on the collection of the Museu de Ciências Naturais da Fundação Zoobotânica do Rio Grande do Sul, Nr. 33125, holotype and Nr. 33126, paratypes. Detailed morphological and anatomical characters as well quantative data are given.
Gastropoda; Veronicellidae; Semperula; new species