A genus within the family Douvillinidae of the order Strophomenida from the Erdaogou Member of the Xibiehe Formation in the Early Devonian of central Jilin has been re-examined, with consideration
given to the 56 specimens collected and described by Liu and Huang (1977). Based on its distinct external ornamentation and internal characteristics, it has been classified as Cymostrophia (Protocymostrophia). It is
concluded that the three specices described by Liu and Huang (1977), Idioglyptus alatus, I. semicircularis, I. subquadratus, as well as the Mesodouvillina jilinensis Su, 1980 should be considered synonyms and be
named Cymostrophia (Protocymostrophia) alatus (Liu) Li.