Shell size to 38 mm; shell similar to Crepidula fornicata, but with internal septum straight, muscle scar under right edge of septum. Color white with small, well-defined brown spots. As most species in the family, C. maculosa broods the eggs in capsules stored between the head and the foot (photo). The egg capsules contain each between 10-20 eggs only (last photo), which develop into miniature adults inside the capsules, bypassing a free-swimming larval stage. Photo of female snail with eggs by Amy Tripp, February 2021.