A high resolution micrograph showing the partially open cytoproct of Colpoda cucullus. The alveoli stop at the edges of the cytoproct and filamentous material (actin?) coats the inside of the single membrane that covers the open cytoproct. TEM taken on 5/3/69 by R. Allen with Philips 300 operating at 60kV. Neg. 14,800X. The raw film was digitized by scanning with a Nikon Coolscan 9000ED. This image is suitable for quantitative analysis. Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections were prepared at approximately 75nm thickness. Additional information is available at (http://www5.pbrc.hawaii.edu/allen/).