The Auclair ground to be acquired in modest staged payments features 11m of visual pegmatite including spodumene in drill core from a depth of around 200m.
A formal assay result is awaited.
The drilling was from 2010.
Cygnus is paying about C$250,000 cash and issuing one million shares to Osisko, with a further $3 million in cash or shares payable upon an inferred resource estimate of not less than 3 million tonnes grading not less than 1.2% lithium oxide.
Payment of $3 million in cash or shares is also payable should Cygnus have gold success and outline 1 million ounces at 3 grams per tonne or better.
Cygnus now has claims over 330sq.km of ground in "this world-class lithium province".
The David Southam-led Cygnus had cash at the end of December of A$13.6 million.
It raised $8 million in December at 44c per new share.
Those shares were this week at 31.5c, capitalising the company at $58 million.
Cygnus is a Steve Parsons, Ray Shorrocks, Michael Naylor and Michael Bohm-backed junior.
