Blood cells of Ecteinascidia sp. stained with 2,2-bipyridine, viewed under compound microscope with Tuscon camera system at 40X magnification. (a) Signet ring cell (black arrow). Morula cell (white arrow). Scale bar = 10μm. (b) Signet ring cell (black arrow). Lymphocyte (white arrow). Phagocyte (black arrowhead). Vacuolated amoebocyte (white arrowhead). Scale bar = 10μm. (c) Vanadocyte; probable compartment cell type II (black arrowhead). Scale bar = 10μm. (d) Vanadocyte; probable compartment cell type II (black arrowhead). Scale bar = 10μm.