Leo & Leo Minor
The Lion and The Little Lion
Yin and Yang is an ancient Chinese way of thinking. Basically it says their are two elemental forces in nature the Greater and the Lesser. In this case Leo of the Zodiac is the Greater while Leo Minor is the Lesser.
The Astrological Symbol for Leo Minor is similar the 'Leo Major' - except it is a lowercase 'q' with a backwards 's' squiggle.