DEVONIAN CISTIMORPH RUGOSE CORALS FROM TH E SW OF THE QINLING MOUNTAINS

In this work different species and subspecies of cystimorph Rugose Cor als coming from the lower half of the Dangduo Formation (Upper Emsian) and Lure Formation (Eifelian), Tewo District (Gansu Province, Central China), are described in detail. Five taxa, Cayugaea aff, gansuensis CAO, C. aff. cylindrica (BULVANKER), Mesophyllum (Cystiphylloides) sec undum ssp. A, M. (C.) secundum ssp. B and Mesophyllum (Mesophyllum) af f, arrectum (YU & CAI) probably correspond to new forms. Regarding the rest of the species and subspecies, Mesophyllum (Cystiphylloides) fon gi (YOH), M. (C.) caespitosum (SCHLUTEB) and M. (C.) ef. macroeystis P nacrocystis (SCHLOTEB), the stratigraphical range in China is extended . The rest of the species had been cited and described before by other authors from the same district. Finally, on the basis of the analysis of the stratigraphical and geographical distribution of the taxa stud ied, new data are given which support the paleobiogeographical hypothe sis proposed by other authors. A relationship among Central China, NW Canada, Europe and S China, during the Upper Emsian-Eifelian, is shown .