ATLAS OF PHYTOPLANKTON FROM MEDITERRANEAN SEA.- This work constitute a representative sample of phytoplanktonic organisms from the Mediterranean Sea presented in scanning electron microscopy images, which are complemented with drawings. The content include 251 taxa, which 135 are dinoflagellates, 80 diatoms, 21 coccolithophorids and 15 other organisms. The terminology used is up to date, sinonims are presented and the organisms are briefly described at genus level. The material proceed from diverse expeditions carried out between 1982 and 1989.