The superficial glial limiting membrane (SGLM) of the parietal and cerebellar cortices and the spinal cord was studied in the adult cat by transmission and scanning electron microscopy. The SGLM of the parietal cortex was generally thick, and it consisted of protoplasmic astrocytes and their processes. These processes varied in shape, and they were complexly interwined. The processes included foot processes, consisting of the end-feet and the ascending processes, sheet-like processes, cylindrical processes, thick processes with large extensions, and other processes with irregular outlines. The end-feet in the parietal cortex had numerous, denticular processes and a few cylindrical and sheet-like processes. The thick processes extended cylindrical, secondary processes. The SGLM of the cerehellar cortex consisted primarily of end-feet originating from Bergmann cells, and secondarily of marginal, subpial astrocytes generally arranged in a single layer. The end-feet on the cerebellar cortex were disk-like, with numerous denticular processes. The SGLM of the spinal cord consisted of fibrous astrocytes. Their processes were less complex than those in the parietal cortex, and also contained foot processes, consisting of end-feet and ascending processes, and cylindrical processes. The end-feet had numerous, fine processes and some long, unbranched processes.