Based on their compositions and characteristics as well as resemblanceand difference between the most abundent genera and spicies

six foramini-feral faunas are recognized

namely:1.the Discorbis fauna

2.the Nummu-lites fauna

3.the Cibicides fauna

4.the Orbulina-Miogypsina fauna

5.the Ammonia fauna and 6.the Pulleniatina-Asterorotalia fauna.The firstthree of them belong to the early Tertiary while the last three to the late Tertiary.The Discorbis fauna are mainly found in many places of East China

suchas the Bohai gulf

the Jianghan basin

the north part of Jiangsu province

the Sanshui basin

etc.The Ammonia fauna are mainly reported from the W.Tarim basin.As they may tolerate some lowering of salinity

they serveas important facial indicators in searching for oil and gas reservior of brackish-water origin.The Cibicides fauna and the Orbulina-Miogypsina faunacomprising entirely shallow marine and pelagic genera play an improtant rolein prospecting for oil and gas reservior of epeiric origin.The Cibicides faunais discovered from the S.W.border of Tarim

while the Orbulina-Miogy-psina fauna has much wider distribution in Taiwan province and the Leiqiong region of Guangdong province

and on the continental shelf of the South and East China Seas.