At Changshankou and Yehli in Kaiping Basin,the late Cambrian stratigraphy andpaIaeontology was first studied by Prof.Y.C.Sun in 1920.The following two forma-tions were then sectioned:2.Fengshan formation characterized by Prychaspis subglobosa,Mansuyia orientalis1.Changsban formation yielding Changshania conica,etc.In 1929,Y.T.Cbao,T.F.Hou and C.Y.Lee went to Yehli for a detailed mappingof the Fengshan-Weishan section,but they failed to obtain any other late Cambrian fos-