What is the fascia called that separates muscle fibers from one another within a fascicle?

The endomysium is the connective layer of tissue that surrounds and separates individual muscle fibers called myofibrils.  The endomysium is the smallest layer of connective tissue in skeletal muscle.  One function of connective tissue is to encapsulate and protect the individual structures of the muscle fiber that are critical to the functioning of the muscle.  Specifically, the endomysium directly protects the sacrolemma, which functions as a membrane for muscle fibers.  The sacrolemma maintains homeostasis within the fiber by regulating the extracellular and intracellular fluids.  This also includes regulation of electrolytes, specifically sodium and postassium, during muscle contractions.