V.ORNATUS and V.NILOTICUS
Note the differences:
BANDS of OCELLI (yellow spots): Counting the bands from the shoulder to the hips (not where the tail begins), on ornates, there should be five, whereas on commons, there will be seven.
TONGUE COLORATION: Ornates have a pink tongue with a reddish or purple tint compared to commons with a bluish black tongue.
SHAPE OF HEAD: Ornates have a blunt, boxlike appearance compared to commons which have narrow, wedgelike shapes.
SIZE: Ornates, with their stocky, muscular build, can get to a (STL) length of 6 feet (180 cm), whereas the commons, with their slim, streamlined build, can get even longer, up to 7 feet (210 cm) in their adult life.
LITTLE NESSIE and SPENCER
In these two pics, Little Nessie, an ornate, is the one above the other, Spencer, a common nile.