Both players joined Saints for the start of pre-season and played in the friendlies against Ayr, Dumbarton and Brechin. Neither really stood out - although Glass scored in the game at Somerset. He then got injured, so it's no surprise he wasn't signed.
Lynch was let go by Falkirk in the summer, having played just 10 times over the course of the last two seasons. He'd started his career at Hibs but hadn't exactly set the heather on fire there either. It's another weird signing - we're short of midfielders but he's probably not the answer, and he's another defensive option rather than an attacking one.
Story source: The Official St. Mirren Website