Ⅰ.INTRODUCTION The Devonian has been known in China since 1920 through the workof Grabau and C.C.Tien(on brachipods),Y.C.Sun and K.K.Chao(onammonites),Y.C.Sun,Y.S.Chi,C.C.Yu and H.C.Wang(on corals),butthe Upper Devonian stratigraphy of China remains obscure.Grabau first pointed out the fact that the Clymenia fauna originated inthe Boreal Sea and widely distributed in Northern Europe such as SouthernEngland,Western France,Poland,and also the Pyrence,and the Alps.Thiscan be clearly indicated by the fact that the Clymenia fauna is well developed inthe rocks of the Ural geosyncline,and Southern Russia appears to be the onlypossible line of their connection.Thus,the Boreal sea was connected withboth the Caledonian and Uralian Geosynclinès,which laid along the periphery