RESTUDY ON THE TRILOBITES (ASAPHIDS,NILEIDS, AND ILLAENIDS) FROM THE MIAOPO FORMATION(UPPER ORDOVICIAN) IN EASTERN YANGTZE GORGE AREA,WESTERN HUBEI

• 峡东地区庙坡组栉虫类、宝石虫类和斜视虫类三叶虫