A New Species of Foraminiferida from the Miocene of South Louisiana

Abstract

A new species of nodosarine Foraminif erida is described and illustrated. Lenticulina (R.obulus) cristi, sp. nov., is an important stratigraphic marker which occurs above Cibicides carstensi opima Cushman and Ellisor and below Bigenerina huniblei Cushman and Ellisor in the middle Miocene of South Louisiana. Stratigraphic marker fossils in the subsurface of South Louisiana are essential to comprehension of the complex stratigraphy and, in fact, provide the means of establishing regional correlations in the area. The middle Miocene sediments form a prolific producing trend of great interest to Gulf Coast geologists. The purpose of this note is to describe and illustrate one of the foraminif eral species characteristic of this interval which has not been formally named. This form, commonly referred to as 11Cristellaria I'', occurs most prominently above Cibicides carstensi opima Cushman and Ellisor and below Bigenerina humblei Cushman and Ellisor in the neritic sediments of the middle Miocene of Somh Louisiana. It is one of the more prominent species in the "Krumbhaar fauna" which is considered reliable for regional correlation.