A high resolution micrograph of the transverse microtubular ribbon, consisting of ~3 microtubules, extends to the cell's left of the basal body and rises to the top of the ridge where it ends. Thus the proximal end of a pair of basal bodies is firmly anchored by this “tripod” of accessory structures, the kd, pc mt and tr mt. Presumably this tripod will resist the torque induced on the basal bodies by the movements of the ciliary beat and hold the proximal ends of the basal body in a relatively rigid position. Septa of the alveolar sac system and septal pores are seen in this micrograph. Internally extruded trichocysts also seen in this micrograph. TEM taken on 1/12/73 by R. Allen with Hitachi HU11A operating at 75kV. Neg. 9,900X. The raw film was scanned with an 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/).