A cell with a flat alveolar sac system. It is not clear why some cells have expanded alveoli and others have flattened alveoli. Cacodylate buffered fixative. TEM taken on 2/3/69 by R. Allen with Phil...

Cross sections of striated bands and infraciliary lattice arms. Filaments of the striated bands are less densely packed than the infraciliary lattice. Kinetodesmal fibers and postciliary microtubules ...

Planar view of the cortex demonstrating that the striated bands do indeed link the internal slopes of one cortical unit with all surrounding units. Parasomal sacs lie to the side of a single basal bod...

Striated band spanning the base of a longitudinal ridge (kinetodesmal fibers are seen in the ridge in cross section). The epiplasm appears absent from the top of the ridge or is replaced by two thicke...

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 signif...

Septa of bordering alveoli when lying in the plane of section exhibit pores at their outer margins closest to the plasma membrane. This shows that there is physical continuity between the lumens of al...

A view of cortical fibers except the observer is looking at a cross-sectioned cell as though from anterior toward the posterior end of the cell; in this view the kd sections are seen on the left side ...

Longitudinal section of a striated band lying superficially to an arm of the infraciliary lattice but not contacting it. A post is seen at the junction of a branch in the infraciliary lattice. TEM tak...

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 signif...

The pellicular pore consists of the invaginated plasma membrane that penetrates the alveolus as well as the epiplasm and ends as a clathrin-coated pit. TEM taken on 3/14/72 by R. Allen with Hitachi HU...