The term lamina rara refers to a layer of the cerebral cortex that is of lesser visual density than the layers adjacent to it. The cell density is low, so it appears light in cell stains. A well known example is in the rostral entorhinal cortex, where the lamina rara is sometimes termed a separate layer and sometimes considered part of the layer superficial to it. The term was used by early cortical histologists but is not common today (J. Price, personal communication).