The acidosome-like vesicle has at least 2 enclosing membranes or one membrane indented back on itself and an internal electron-opaque tongue-like droplet that is continuous with the enclosing membranes at one end of the vesicle and may arise by invagination of these membranes into the vesicle’s interior. Such vesicles do not resemble lysosomes of any other organism, including Paramecium. Lysosome membranes should be thicker and be coated by a heavy glycocalyx and exhibit latency. There is no glycocalyx seen here. TEM taken on 8/15/67 by R. Allen with Philips 200 operating at 60kV. Neg. 19,200X. The raw negative was scanned with an Epson Perfection V750 Pro and this high resolution image is best used for quantitative analysis. Additional information available at (http://www5.pbrc.hawaii.edu/allen/).