Ascidiae - Seescheiden (IMAGE) Xi'an Jiaotong-Liverpool University Caption There are many varieties of sea squirts (Ascidiae). Some are shown in Ernst Haeckel's Kunstformen der Natur (1904). Credit Ernst Haeckel Usage Restrictions No restrictions. License CC0 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.