Ryan,
Yes, it sounds like you describing bryozoans. They are fairly common at Hillsdale. I saw them quite regularly when I had Hillsdale in my district from 1997 to 2003.
Here's a CDC post from a few years ago that contains some additional info on bryozoans. Scroll down to post #189... http://www.crappie.com/crappie/ask-t...ml#post1298629
Hope this helps!