Freeze fracture of the plasma membrane and outer alveolar membrane of the pellicle of V. microstoma. The surface of Vorticella is encircled by rings which follow the septa of underlying alveoli. In this fracture one can see the fractured necks of the continuities between the outer and inner alveolar membranes (latter not visible). The outer alveolar membrane has many prominent IMPs on its P-fracture face. Septal pores extend between the continuities, thus the alveoli are all interconnected. The E-fracture face of the plasma membrane has only a moderate number of prominent IMPs compared to its P face. TEM taken on 11/11/75 by R. Allen with JEM 100B operating at 80kV. Neg. 14,579X. 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/).