Complementary freeze‐fracture replicas and high resolution tantalum‐tungsten shadowing have been used in a study of the membanes of the marine alga Chrysochromulina chiton. Membrane particle populations range from 38/100 nm2 in the plastid to 2/100 nm2 in the pyrenoid cap membrane. Membrane asymmetry was evident in all membranes, but was most obvious in those with higher particle numbers. In all complementary replica pairs, particles were always more numerous on protoplasmic fracture faces. Small, particle‐free areas with bordering particles were also seen as recurring membrane features. Complementarity of matching fracture faces was seen for very small background granularity patterns and for large membrane components, but not for particles. Complementarity can also be seen in non‐membranous fracture faces both within and external to the cell, suggesting the presence of polymeric materials in these areas that produce “particles” due to plastic deformation.