The mangrove periwinkle, Littorina angulifera, is a common intertidal snail in mangrove forests of the southeast United States. The shell color of L. angulifera varies from bluish white, orange to dull yellow, reddish brown to grayish brown (Andrews 1994). The shell is comprised of 6 whorls, with the body whorl about half of the total height of the snail. Darker dashes on the ribs of the shell are often fused to form stripes on the body whorl. The early whorls around the base bear regularly-spaced vertical white spots below the channeled sutures.