What is the difference between the basal membrane and the basal lamina?
The basal lamina is a specialised type of extracellular matrix. It is found on the basal side of all epithelial tissue but can also surround other cell types like myocytes and adipocytes. It is also called the basement membrane, although it is not the traditional plasma membrane that we have come to know and love. Rather, it is composed of proteins (often glycosylated) and polysaccharides.

The basal membrane is the actual plasma membrane on the basal side of an epithelial cell (adjacent to the basal lamina/basement membrane).