This paper deals with the results of the analyses made on the planktonic faunas collected from the Miocene foraminiferal assemblages of Moriones, Malinta, and Tarlac formations, along the Aksitero River and Tarlac-Burgos Roadsections, west side of Tarlac province, Luzon Central Valley. Forty-three species, subspecies and varieties of planktonic Foraminifera are identifiel and their relative abundance and significant occurrences in their respective sequences are shown in the tables. A twofold faunal division based on occurrences of diagnostic planktonic species is recognized in the Moriones formation. Using the relative abundance of the planktonic and benthionic species, a summary of the ecologic features and basinal development in the region is given, together with a brief liscussion of the lithologic and faunal characteristic of the three geologic formations.

Tables illustrating the relative distribution of the forty-three species belonging to ten genera of the families of Hantkoninidae, Orbulinidae, and Globorotaliidae are included.