Some early tertiary ostracods from West Pakistan.

Ostracoda from the Palaeocene of the Sor Range and from the Palaeocene and Eocene of the Rakhi Nala, Zao River and Shpalai Khwara sections, Sulaiman Range, West Pakistan, have been examined The family TRACHYLEBERIDIDAE has been studied in detail. It is represented by fourteen genera, 4subgenera and sixty-one species. Four new genera (Alocopocythere, Gyrocythere, Phalcocythere and Stigmatocythere) and two new subgenera (Paracosta and Scelidocythereis) are proposed. Out of the sixty-one species described, fifty-two are new. The Palaeocene and Eocene of the Rakhi Nala section is divided into five ostracod biostratigraphic units. The biostrati graphic units IV and V of the Rakhi Nala are represented in the Zao River section and have almost identical ostracod faunas. The biostratigraphic unit IV of the Rakhi Nala is also represented in the Shpalai Khwara section. The Equations of Correlation between the Rakhi Nala and Zao River sections for biostratigraphic unit V (i.e. Middle - Upper Eocene) have been calculated by means of ranges of ostracod species common to the two sections. The standard errors of estimate for the Equations of Correlation have also been calculated. The boundaries between the Palaeocene - Lower Eocene, Lower - Middle Eocene and Middle - Upper Eocene in the Sulaiman Range are discussed