Full Idea
Aristotle's theory also includes a special group of forms that can exist without matter, of which the Prime Mover is an instance, and these forms are separate not only in account but also in existence.
Gist of Idea
Some forms, such as the Prime Mover, are held by Aristotle to exist without matter
Source
report of Aristotle (Metaphysics [c.324 BCE]) by Mary Louise Gill - Aristotle on Substance Ch 1
Book Reference
Gill,Mary Louise: 'Aristotle on Substance: Paradox of Unity' [Princeton 1989], p.35
A Reaction
I am curious about her other examples. This must be the closest that Aristotle gets to his teacher's view of the Forms.