CONTENTS 1
Preface……………………………………………………………………Mu En-zhiResearch Work on Ordovician—Silurian Boundary in China Mu En-zhi 1
The Ordovician—Silurian Boundary in Yichang,Hubei Mu En-zhi,Zhu Zhao-ling,Lin Yao-kun and Wu Hong-Ji 15
Graptolites from the Ordovician—Silurian Boundary Sections ofYichang Area,W．Hubei Mu En-zhi and Lin Yao-kun 45
The Dalmanitina Fauna（Trilobite）from Huanghuachang and Wangjiawan,Yichang County,Hubei Province Zhu Zhao-ling and Wu Hong-ji 83
Brachiopods of Latest Ordovician in the Yichang District,WesternHubei,Central China Rong Jia-yu 111
On the Material of Glyplograptus persculptus（Salter）from the YangziGorges,China Chen Xu and Lin Yao-kun 191
Glyptograptus persculptus Zone——the Earliest Silurian Graptolite Zonefrom Yangzi Gorges,China Lin Yao-kun and Chen Xu 203
A Preliminary Study of Paleomagnetism on the Geological Boundaries ofHuanghuachang Section in Yichang Area Ye Su-juan 233
Rb-Sr Dating of Lower Silurian Black Shale in Huanghuachang,Yichang Hu Hua-guang,Zhang Ren-hu and Zhao Dong-zhi 243
Correlation of Ashgill Graptolite Faunas of Central China and ArcticCanada,with a Description of Diceratograptus cf. mirus Mu fromCanada Chen Xu and A．C．Lenz 247
Upper Ashgillian Chitinozoa from Renhuai,Northern Guizhou Geng Liang-yu,Hu Zhao-xun and Gong Lian-zan 259
Late Ashgillian Glaciation——Effects of Eustatic Fluctuations on theUpper Yangtze Sea Geng Liang-yu 269
Ordovician—Silurian Boundary Section from Jingxian,South Anhui Li Ji-jin,Qian Yi-yuan and Zhang Jun-ming 287
Graptolites Across the Ordovician—Silurian Boundary from Jingxian,Anhui Li Ji-jin 309
The Graptolite Fauna of the Ordovician—Silurian Boundary Section inYuqian,Zhejiang Ge Mei-yu 389
A Species of Dalmanitina（Trilobite）from Deqing and Yuqian Counties,Western Zhejiang Wu Hong-ji 455
On the Baota（Pagoda）Formation Chen Ting-en and Zou Xi-ping 467
Chitinozoa from the Fenhsiang, Hunghuayuan and Dawan Formationsof Huanghuachang,Yichang,Hubei Geng Liang-yu 509