This month's Natural Mystery comes to us from the Boundary Waters Canoe Area Wilderness, courtesy of Kirsten Welge. These two objects were found in shallow water on a stony outcrop near a campsite on Alpine Lake. They were moved to shore to photograph. The question is "What are these?"

An ideal answer will identify these objects as specifically as possible, including naming any organisms that may have been responsible for them appearing where they were found; explain how you arrived at your answer; and detail how you eliminated other possible explanations. Sharing these details will help others benefit from your process.

Answers are due by November 1.