Siphonifera (IMAGE) University of Southampton Caption Globigerinella siphonifera, a species of macroperforate planktonic foraminifera less than a millimetre in diameter. Credit GLOW research cruise. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.