In addition to plates the plasma membrane contains IMPs on its P-fracture face in ring or parenthesis shape at sites of trichocyst secretion. A ring actually consists of two circles of IMPs and signifies that a trichocyst is docked underneath while a parenthesis means the site has no docked trichocyst. The fracture also exposed some of the E-face of the outer alveolar membrane which is relatively free of IMPs. TEM taken on 6/4/90 by R. Allen with Zeiss 10A operating at 80kV. Neg. 19,800X. 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/).