I've found two of these inside rotting logs. They move on a moist, sticky foot like snail, but more slowly, and have a feelered or tentacled extension that sometimes extends out from under the odd macrame-like carapace. Note the "turret" at rear of carapace. Carapace feels tough but not hard.

The one pictured went into stasis in mid-March, and it hatched into a deformed wingless adult