Layer of the entorhinal cortex that is most superficial, continuous with layer 1 of adjacent neocortex and the molecular layer of the subiculum, lying deep to the pial layer and superficial to layer 2. It is relatively acellular consisting mostly of fibers running transversely relative to the cortical surface (Adapted from Paxinos, G. The rat central nervous system, 2nd ed, Academic Press, San Diego, 1995, pg. 474) [ ]