Contents

29 June 1973
Vol 180, Issue 4093

About The Cover

Scanning electron micrograph of Valacerta sidera(Schulz), a Late Cretaceous silicoflagellate speices, from Fletcher's Ice-Island (T-3) core 437 sediments from tje Alpha Cordillera of the Arctic Ocean (original size from tip of vertical point to base of star-shaped figure, 80 micrometers). See page 1360. [H.Y. Ling and Linda M. Mcpherson, University of Washington, Seattle; D. L. Clark, University of Wisconsin, Madison]