CAMERON, ROY E. & DEVANEY, JOHN R. 1970. Antarctic soil algal crusts: Scanning electron and optical microscope study. Trans. Amer. Micros. Soc. 89: 264-273. Two algal soil crusts from South Victoria Land, Antarctica were chosen for study with the scanning electron microscope, and a comparison study was made with the light transmission microscope. Soils were investigated microscopically without treatment, and following incubation in moist chambers and in dilution cultures. By scanning electron microscopy, algae were readily discerned in association with soil particles as flowing and entwined masses which bound soil particles together, but individual species were usually not readily identified within community associations. Structure of trichomes was obscured by sheath material, but some naked trichomes were observed. The algal crust components were primarily closely related oscillatorioid blue-green algae: Schizothrix calcicola (Ag.) Gom., S. arenaria (Berk.) Gom., and S. rubella Corn. Globose colonies of Nostoc commune Vauch, were observed by both scanning electron microscopy and light microscopy. A rarely encountered form of N. commune vas observed as Hydrocoryne spongiosa Schw. The only green alga present was Chlorella vulgaris Beij. It was concluded that the scanning electron microscope is a new and valuable tool in the investigation of microbial associations of a soil algal collmmnity, but the light transmission microscope is still useful for routine identification of the soil algal components.