A high resolution image of the pellicle of Opercularia coarctata. Indentations of the plasma membrane penetrate the alveolar membranes end as coated pits. These pits are also known as pellicular pores are homologous to parasomal sacs of other ciliates. The surface ridges contain an electron opaque rod in the cytosol of unknown composition, seen here in cross section. TEM taken on 6/11/69 by R. Allen with Philips 300 operating at 60kV. Neg. 30,000X. The raw film was scanned with a Epson Perfection V750 Pro. This image is best used for quantitative analysis. Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections prepared at approximately 75nm thickness. Additional information available at (http://www5.pbrc.hawaii.edu/allen/).