The Marsh Periwinkle Litoraria irrorata has been well-studied and is a conspicuous, dominant-player in the ecology of salt marshes along the East Coast of the United States. I took these photographs to prepare for a mark-recapture exercise that my Coastal Ecology course performed. Unfortunately, I couldn’t attend the exercise, and it was run by my department chair, who is co-teaching the course with me. From the images the students captured, and have posted, the activity seemed productive and fun.